diff --git a/integrationtest/channelserializer/main.d b/integrationtest/channelserializer/main.d
index 30577f99..e6691918 100644
--- a/integrationtest/channelserializer/main.d
+++ b/integrationtest/channelserializer/main.d
@@ -85,7 +85,7 @@ int main ( istring[] args )
     {
         auto ser = new ChannelSerializer!(S)("failed_channel");
 
-        void dumpRecord ( void delegate ( hash_t, ref Contiguous!(S) ) record_dg )
+        void dumpRecord ( scope void delegate ( hash_t, ref Contiguous!(S) ) record_dg )
         {
             throw new Exception("File write error");
         }
diff --git a/src/dhtproto/client/DhtClient.d b/src/dhtproto/client/DhtClient.d
index 9693aece..1bdcde39 100644
--- a/src/dhtproto/client/DhtClient.d
+++ b/src/dhtproto/client/DhtClient.d
@@ -403,7 +403,7 @@ public class DhtClient : IClient
 
         ***********************************************************************/
 
-        public void opCall ( RequestParams.GetBoolDg output,
+        public void opCall ( scope RequestParams.GetBoolDg output,
             NotifierDg user_notifier )
         {
             this.reset(output, user_notifier);
@@ -428,7 +428,7 @@ public class DhtClient : IClient
 
         ***********************************************************************/
 
-        private void reset ( RequestParams.GetBoolDg output,
+        private void reset ( scope RequestParams.GetBoolDg output,
             NotifierDg user_notifier )
         {
             this.output = output;
@@ -686,8 +686,8 @@ public class DhtClient : IClient
 
     ***************************************************************************/
 
-    public void nodeHandshake ( RequestParams.GetBoolDg output,
-        RequestNotification.Callback user_notifier )
+    public void nodeHandshake ( scope RequestParams.GetBoolDg output,
+        scope RequestNotification.Callback user_notifier )
     {
         this.node_handshake(output, user_notifier);
     }
@@ -759,8 +759,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public Put put ( Key ) ( cstring channel, Key key, RequestParams.PutValueDg input,
-                             RequestNotification.Callback notifier )
+    public Put put ( Key ) ( cstring channel, Key key, scope RequestParams.PutValueDg input,
+                             scope RequestNotification.Callback notifier )
     {
         return *Put(DhtConst.Command.E.Put, notifier).channel(channel).key(key)
             .io(input).contextFromKey();
@@ -799,8 +799,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public Get get ( Key ) ( cstring channel, Key key, RequestParams.GetValueDg output,
-            RequestNotification.Callback notifier )
+    public Get get ( Key ) ( cstring channel, Key key, scope RequestParams.GetValueDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *Get(DhtConst.Command.E.Get, notifier).channel(channel).key(key)
             .io(output).contextFromKey();
@@ -837,8 +837,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public Exists exists ( Key ) ( cstring channel, Key key, RequestParams.GetBoolDg output,
-            RequestNotification.Callback notifier )
+    public Exists exists ( Key ) ( cstring channel, Key key, scope RequestParams.GetBoolDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *Exists(DhtConst.Command.E.Exists, notifier).channel(channel)
             .key(key).io(output).contextFromKey();
@@ -870,7 +870,7 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public Remove remove ( Key ) ( cstring channel, Key key, RequestNotification.Callback notifier )
+    public Remove remove ( Key ) ( cstring channel, Key key, scope RequestNotification.Callback notifier )
     {
         return *Remove(DhtConst.Command.E.Remove, notifier).channel(channel)
             .key(key).contextFromKey();
@@ -915,8 +915,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetAll getAll ( cstring channel, RequestParams.GetPairDg output,
-            RequestNotification.Callback notifier )
+    public GetAll getAll ( cstring channel, scope RequestParams.GetPairDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *GetAll(DhtConst.Command.E.GetAll, notifier).channel(channel)
             .io(output);
@@ -960,8 +960,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetAllKeys getAllKeys ( cstring channel, RequestParams.GetValueDg output,
-            RequestNotification.Callback notifier )
+    public GetAllKeys getAllKeys ( cstring channel, scope RequestParams.GetValueDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *GetAllKeys(DhtConst.Command.E.GetAllKeys, notifier)
             .channel(channel).io(output);
@@ -1004,8 +1004,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public Listen listen ( cstring channel, RequestParams.GetPairDg output,
-            RequestNotification.Callback notifier )
+    public Listen listen ( cstring channel, scope RequestParams.GetPairDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *Listen(DhtConst.Command.E.Listen, notifier).channel(channel)
             .io(output);
@@ -1047,8 +1047,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetChannels getChannels ( RequestParams.GetNodeValueDg output,
-            RequestNotification.Callback notifier )
+    public GetChannels getChannels ( scope RequestParams.GetNodeValueDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *GetChannels(DhtConst.Command.E.GetChannels, notifier).io(output);
     }
@@ -1088,7 +1088,7 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetSize getSize ( RequestParams.GetSizeInfoDg output, RequestNotification.Callback notifier )
+    public GetSize getSize ( scope RequestParams.GetSizeInfoDg output, scope RequestNotification.Callback notifier )
     {
         return *GetSize(DhtConst.Command.E.GetSize, notifier).io(output);
     }
@@ -1131,7 +1131,7 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetChannelSize getChannelSize ( cstring channel, RequestParams.GetChannelSizeInfoDg output, RequestNotification.Callback notifier )
+    public GetChannelSize getChannelSize ( cstring channel, scope RequestParams.GetChannelSizeInfoDg output, scope RequestNotification.Callback notifier )
     {
         return *GetChannelSize(DhtConst.Command.E.GetChannelSize, notifier)
             .channel(channel).io(output);
@@ -1165,7 +1165,7 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public RemoveChannel removeChannel ( cstring channel, RequestNotification.Callback notifier )
+    public RemoveChannel removeChannel ( cstring channel, scope RequestNotification.Callback notifier )
     {
         return *RemoveChannel(DhtConst.Command.E.RemoveChannel, notifier)
             .channel(channel);
@@ -1206,8 +1206,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetNumConnections getNumConnections ( RequestParams.GetNumConnectionsDg output,
-            RequestNotification.Callback notifier )
+    public GetNumConnections getNumConnections ( scope RequestParams.GetNumConnectionsDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *GetNumConnections(DhtConst.Command.E.GetNumConnections, notifier)
             .io(output);
@@ -1250,8 +1250,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetVersion getVersion ( RequestParams.GetNodeValueDg output,
-            RequestNotification.Callback notifier )
+    public GetVersion getVersion ( scope RequestParams.GetNodeValueDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *GetVersion(DhtConst.Command.E.GetVersion, notifier).io(output);
     }
@@ -1292,8 +1292,8 @@ public class DhtClient : IClient
         mixin RequestParamsSetup; // private setup() method, used by assign()
     }
 
-    public GetResponsibleRange getResponsibleRange ( RequestParams.GetResponsibleRangeDg output,
-            RequestNotification.Callback notifier )
+    public GetResponsibleRange getResponsibleRange ( scope RequestParams.GetResponsibleRangeDg output,
+            scope RequestNotification.Callback notifier )
     {
         return *GetResponsibleRange(DhtConst.Command.E.GetResponsibleRange,
             notifier).io(output);
@@ -1316,7 +1316,7 @@ public class DhtClient : IClient
     ***************************************************************************/
 
     override protected void scopeRequestParams (
-        void delegate ( IRequestParams params ) dg )
+        scope void delegate ( IRequestParams params ) dg )
     {
         scope params = new RequestParams;
         dg(params);
diff --git a/src/dhtproto/client/helper/ChannelSerializer.d b/src/dhtproto/client/helper/ChannelSerializer.d
index 3b6fd933..eaa21157 100644
--- a/src/dhtproto/client/helper/ChannelSerializer.d
+++ b/src/dhtproto/client/helper/ChannelSerializer.d
@@ -97,7 +97,7 @@ public class ChannelSerializer ( S )
 
     public this ( istring path )
     {
-        const buffer_size = 64 * 1024;
+        static immutable buffer_size = 64 * 1024;
 
         this.path = path;
         this.buffered_output = new BufferedOutput(null, buffer_size);
@@ -124,7 +124,7 @@ public class ChannelSerializer ( S )
 
     public bool dump ( Contiguous!(S)[hash_t] aa, bool block = false )
     {
-        void dumpAA ( void delegate ( hash_t, ref Contiguous!(S) ) dump_record )
+        void dumpAA ( scope void delegate ( hash_t, ref Contiguous!(S) ) dump_record )
         {
             foreach ( k, v; aa)
                 dump_record(k, v);
@@ -148,7 +148,7 @@ public class ChannelSerializer ( S )
 
     public bool dump ( Map!(Contiguous!(S), hash_t) map, bool block = false )
     {
-        void dumpMap ( void delegate ( hash_t, ref Contiguous!(S) ) dump_record )
+        void dumpMap ( scope void delegate ( hash_t, ref Contiguous!(S) ) dump_record )
         {
             foreach ( k, v; map)
                 dump_record(k, v);
@@ -171,7 +171,7 @@ public class ChannelSerializer ( S )
 
     ***************************************************************************/
 
-    public bool dump ( DumpRecordDg record_dump_dg, bool block = false )
+    public bool dump ( scope DumpRecordDg record_dump_dg, bool block = false )
     {
         this.record_dump_dg = record_dump_dg;
         return this.fork.call(block);
@@ -222,7 +222,7 @@ public class ChannelSerializer ( S )
 
     ***************************************************************************/
 
-    public void load ( LoadRecordDg record_load_dg )
+    public void load ( scope LoadRecordDg record_load_dg )
     {
         size_t num_records;
         scope file = new File(this.path, File.ReadExisting);
@@ -346,7 +346,7 @@ unittest
     void dumpChannelFromContainer ( )
     {
         void containerIterator (
-            void delegate ( hash_t, ref Contiguous!(S) ) dump_record )
+            scope void delegate ( hash_t, ref Contiguous!(S) ) dump_record )
         {
             Contiguous!(S) v;
 
diff --git a/src/dhtproto/client/legacy/DhtConst.d b/src/dhtproto/client/legacy/DhtConst.d
index c7f08754..50104dd6 100644
--- a/src/dhtproto/client/legacy/DhtConst.d
+++ b/src/dhtproto/client/legacy/DhtConst.d
@@ -56,7 +56,7 @@ static:
 
     ***************************************************************************/
 
-    public const ApiVersion = "20110401";
+    public enum ApiVersion = "20110401";
 
 
     /***************************************************************************
@@ -66,7 +66,7 @@ static:
 
     ***************************************************************************/
 
-    public const RecordSizeLimit = RecordBatch.DefaultMaxBatchSize;
+    public enum RecordSizeLimit = RecordBatch.DefaultMaxBatchSize;
 
 
     /***************************************************************************
@@ -221,6 +221,6 @@ public struct NodeHashRange
 
     public equals_t opEquals ( NodeHashRange rhs )
     {
-        return this.opCmp(rhs) == 0;
+        return (&this).opCmp(rhs) == 0;
     }
 }
diff --git a/src/dhtproto/client/legacy/common/NodeRecordBatcher.d b/src/dhtproto/client/legacy/common/NodeRecordBatcher.d
index b909d241..03172346 100644
--- a/src/dhtproto/client/legacy/common/NodeRecordBatcher.d
+++ b/src/dhtproto/client/legacy/common/NodeRecordBatcher.d
@@ -95,10 +95,10 @@ public class NodeRecordBatcher
     {
         private hash_t[] hashes;
 
-        public int opApply ( int delegate ( ref hash_t hash ) dg )
+        public int opApply ( scope int delegate ( ref hash_t hash ) dg )
         {
             int r;
-            foreach ( h; this.hashes )
+            foreach ( h; (&this).hashes )
             {
                 r = dg(h);
                 if ( r ) break;
diff --git a/src/dhtproto/client/legacy/internal/helper/ChannelMirror.d b/src/dhtproto/client/legacy/internal/helper/ChannelMirror.d
index ca8cfa95..5eb6e01d 100644
--- a/src/dhtproto/client/legacy/internal/helper/ChannelMirror.d
+++ b/src/dhtproto/client/legacy/internal/helper/ChannelMirror.d
@@ -79,7 +79,7 @@ abstract public class ChannelMirror ( Dht : DhtClient ) : MirrorBase!(Dht)
 
         ***********************************************************************/
 
-        public this ( Dht.RequestNotification.Callback notifier = null )
+        public this ( scope Dht.RequestNotification.Callback notifier = null )
         {
             super(this.outer.dht.listen(this.outer.channel_,
                                         &this.outer.listenReceiveRecord, notifier));
@@ -158,7 +158,7 @@ abstract public class ChannelMirror ( Dht : DhtClient ) : MirrorBase!(Dht)
 
         ***********************************************************************/
 
-        public this ( Dht.RequestNotification.Callback notifier = null )
+        public this ( scope Dht.RequestNotification.Callback notifier = null )
         {
             super(this.outer.dht.getAll(this.outer.channel_,
                                         &this.outer.getAllReceiveRecord,
@@ -273,7 +273,7 @@ abstract public class ChannelMirror ( Dht : DhtClient ) : MirrorBase!(Dht)
 
     public this ( Dht dht, cstring channel,
                   uint update_time_s, uint retry_time_s,
-                  Dht.RequestNotification.Callback notifier = null )
+                  scope Dht.RequestNotification.Callback notifier = null )
     {
         super(dht, channel, update_time_s, retry_time_s);
 
@@ -305,7 +305,7 @@ abstract public class ChannelMirror ( Dht : DhtClient ) : MirrorBase!(Dht)
     public this ( Dht dht, cstring channel,
                   uint update_time_s, uint retry_time_s,
                   lazy ListenRequest listen, lazy GetAllRequest get_all,
-                  Dht.RequestNotification.Callback notifier = null )
+                  scope Dht.RequestNotification.Callback notifier = null )
     {
         super(dht, channel, update_time_s, retry_time_s);
 
@@ -437,8 +437,8 @@ unittest
     // Dummy concrete channel mirror class
     class Mirror : ChannelMirror!(SchedulingDhtClient)
     {
-        const UpdatePeriod = 60; // do a GetAll every 60 seconds
-        const RetryPeriod = 3; // retry failed requests after 3 seconds
+        static immutable UpdatePeriod = 60; // do a GetAll every 60 seconds
+        static immutable RetryPeriod = 3; // retry failed requests after 3 seconds
 
         public this ( SchedulingDhtClient dht, in char[] channel )
         {
diff --git a/src/dhtproto/client/legacy/internal/helper/ExtensibleChannelMirror.d b/src/dhtproto/client/legacy/internal/helper/ExtensibleChannelMirror.d
index d03c920a..b3271d78 100644
--- a/src/dhtproto/client/legacy/internal/helper/ExtensibleChannelMirror.d
+++ b/src/dhtproto/client/legacy/internal/helper/ExtensibleChannelMirror.d
@@ -158,8 +158,8 @@ public class ExtensibleMirror
 
     public this ( Dht dht, cstring channel,
         uint update_time_s, uint retry_time_s,
-        Dht.RequestNotification.Callback request_notifier,
-        PluginNotifier plugin_notifier,
+        scope Dht.RequestNotification.Callback request_notifier,
+        scope PluginNotifier plugin_notifier,
         Plugins plugin_instances )
     {
         super(dht, channel, update_time_s, retry_time_s, request_notifier);
@@ -312,7 +312,7 @@ unittest
             istring toString ( )
             {
                 return format("[{}, {}, {}]",
-                    this.update_time, this.id, this.count);
+                    (&this).update_time, (&this).id, (&this).count);
             }
         }
 
@@ -331,7 +331,7 @@ unittest
         enforce(handshake_ok);
 
         // Add some records to the channel being mirrored
-        const num_records = 10;
+        static immutable num_records = 10;
         for ( hash_t i = 0; i < num_records; i++ )
         {
             mstring put_dg ( DhtClient.RequestContext c )
@@ -520,7 +520,7 @@ public class RawRecordDeserializer ( T )
 
     ***************************************************************************/
 
-    private const bool isVersioned = Version.Info!(T).exists;
+    private static immutable bool isVersioned = Version.Info!(T).exists;
 
     static if (isVersioned)
     {
diff --git a/src/dhtproto/client/legacy/internal/helper/Mirror.d b/src/dhtproto/client/legacy/internal/helper/Mirror.d
index 354b256d..48dbb486 100644
--- a/src/dhtproto/client/legacy/internal/helper/Mirror.d
+++ b/src/dhtproto/client/legacy/internal/helper/Mirror.d
@@ -391,7 +391,7 @@ abstract public class Mirror ( Dht : DhtClient ) : MirrorBase!(Dht)
     ***************************************************************************/
 
     public this ( Dht dht, cstring channel, uint update_time_s,
-        uint retry_time_s, Dht.RequestNotification.Callback notifier = null )
+        uint retry_time_s, scope Dht.RequestNotification.Callback notifier = null )
     {
         super(dht, channel, update_time_s, retry_time_s);
         this.user_notifier = notifier;
@@ -568,8 +568,8 @@ unittest
     // Dummy concrete channel mirror class
     class ExampleMirror : Mirror!(SchedulingDhtClient)
     {
-        const UpdatePeriod = 60; // do a GetAll every 60 seconds
-        const RetryPeriod = 3; // retry failed requests after 3 seconds
+        static immutable UpdatePeriod = 60; // do a GetAll every 60 seconds
+        static immutable RetryPeriod = 3; // retry failed requests after 3 seconds
 
         public this ( SchedulingDhtClient dht, cstring channel )
         {
diff --git a/src/dhtproto/client/legacy/internal/helper/NodeAvailability.d b/src/dhtproto/client/legacy/internal/helper/NodeAvailability.d
index 037a2c60..cd757127 100644
--- a/src/dhtproto/client/legacy/internal/helper/NodeAvailability.d
+++ b/src/dhtproto/client/legacy/internal/helper/NodeAvailability.d
@@ -47,15 +47,15 @@ public struct NodeAvailabilty
 
     public void error ( NodeItem node )
     {
-        if ( auto tracker = node.toHash() in this.error_trackers )
+        if ( auto tracker = node.toHash() in (&this).error_trackers )
         {
             tracker.error();
         }
         else
         {
-            auto tracker = NodeErrorTracker(this);
+            auto tracker = NodeErrorTracker((&this));
             tracker.error();
-            this.error_trackers[node.toHash()] = tracker;
+            (&this).error_trackers[node.toHash()] = tracker;
         }
     }
 
@@ -104,7 +104,7 @@ public struct NodeAvailabilty
 
     public bool available ( NodeItem node )
     {
-        if ( auto tracker = node.toHash() in this.error_trackers )
+        if ( auto tracker = node.toHash() in (&this).error_trackers )
             return tracker.available();
         else
             return true;
@@ -128,7 +128,7 @@ public struct NodeAvailabilty
 
         public void error ( )
         {
-            this.last_error_timestamp = time();
+            (&this).last_error_timestamp = time();
         }
 
         /***********************************************************************
@@ -144,8 +144,8 @@ public struct NodeAvailabilty
 
         public bool available ( )
         {
-            auto diff = time() - this.last_error_timestamp;
-            return diff >= this.outer.retry_delay_s;
+            auto diff = time() - (&this).last_error_timestamp;
+            return diff >= (&this).outer.retry_delay_s;
         }
 
         /***********************************************************************
diff --git a/src/dhtproto/client/legacy/internal/helper/RetryHandshake.d b/src/dhtproto/client/legacy/internal/helper/RetryHandshake.d
index 1da26d06..5441bf8d 100644
--- a/src/dhtproto/client/legacy/internal/helper/RetryHandshake.d
+++ b/src/dhtproto/client/legacy/internal/helper/RetryHandshake.d
@@ -76,8 +76,8 @@ class RetryHandshake
     ***************************************************************************/
 
     public this ( EpollSelectDispatcher epoll, DhtClient dht,
-        size_t wait_time, void delegate ( ) handshake_complete_dg = null,
-        void delegate ( NodeItem ) one_node_handshake_dg = null )
+        size_t wait_time, scope void delegate ( ) handshake_complete_dg = null,
+        scope void delegate ( NodeItem ) one_node_handshake_dg = null )
     {
         this.wait_time = wait_time;
 
@@ -244,18 +244,18 @@ unittest
         // event loop running.
         void main ( )
         {
-            this.epoll = new EpollSelectDispatcher;
-            this.dht = new DhtClient(this.epoll);
+            (&this).epoll = new EpollSelectDispatcher;
+            (&this).dht = new DhtClient((&this).epoll);
             // In a real app, you should call `this.dht.addNodes(...);`
 
             // Start the handshake
             auto retry_delay_seconds = 3;
             // Store the reference to the RetryHandshake
             // object so it doesn't get garbage collected.
-            auto handshake = new RetryHandshake(this.epoll, this.dht, retry_delay_seconds,
-                &this.handshake_complete_dg, &this.node_connected_dg);
+            auto handshake = new RetryHandshake((&this).epoll, (&this).dht, retry_delay_seconds,
+                &(&this).handshake_complete_dg, &(&this).node_connected_dg);
 
-            this.epoll.eventLoop();
+            (&this).epoll.eventLoop();
         }
 
         // Called when an individual node is initially connected.
diff --git a/src/dhtproto/client/legacy/internal/helper/mirror/ContiguousRecordCache.d b/src/dhtproto/client/legacy/internal/helper/mirror/ContiguousRecordCache.d
index 43c08b08..56c47660 100644
--- a/src/dhtproto/client/legacy/internal/helper/mirror/ContiguousRecordCache.d
+++ b/src/dhtproto/client/legacy/internal/helper/mirror/ContiguousRecordCache.d
@@ -152,7 +152,7 @@ unittest
 
         equals_t opEquals ( S rhs )
         {
-            return this.x == rhs.x && this.y == rhs.y && this.s == rhs.s;
+            return (&this).x == rhs.x && (&this).y == rhs.y && (&this).s == rhs.s;
         }
     }
 
diff --git a/src/dhtproto/client/legacy/internal/registry/DhtNodeRegistry.d b/src/dhtproto/client/legacy/internal/registry/DhtNodeRegistry.d
index 2aa083a1..a40ed201 100644
--- a/src/dhtproto/client/legacy/internal/registry/DhtNodeRegistry.d
+++ b/src/dhtproto/client/legacy/internal/registry/DhtNodeRegistry.d
@@ -72,7 +72,7 @@ public class DhtNodeRegistry : NodeRegistry, IDhtNodeRegistryInfo
 
     ***************************************************************************/
 
-    private const expected_nodes = 100;
+    private static immutable expected_nodes = 100;
 
 
     /***************************************************************************
@@ -404,7 +404,7 @@ public class DhtNodeRegistry : NodeRegistry, IDhtNodeRegistryInfo
 
     **************************************************************************/
 
-    public int opApply ( int delegate ( ref IDhtNodeConnectionPoolInfo ) dg )
+    public int opApply ( scope int delegate ( ref IDhtNodeConnectionPoolInfo ) dg )
     {
         int ret;
 
@@ -583,7 +583,7 @@ public class DhtNodeRegistry : NodeRegistry, IDhtNodeRegistryInfo
 
     ***************************************************************************/
 
-    private int opApply ( int delegate ( ref DhtNodeConnectionPool ) dg )
+    private int opApply ( scope int delegate ( ref DhtNodeConnectionPool ) dg )
     {
         int res;
         foreach ( pool; this.nodes.list )
@@ -605,7 +605,7 @@ public class DhtNodeRegistry : NodeRegistry, IDhtNodeRegistryInfo
 
     ***************************************************************************/
 
-    private int opApply ( int delegate ( ref size_t, ref DhtNodeConnectionPool ) dg )
+    private int opApply ( scope int delegate ( ref size_t, ref DhtNodeConnectionPool ) dg )
     {
         int res;
         size_t i;
diff --git a/src/dhtproto/client/legacy/internal/registry/model/IDhtNodeRegistryInfo.d b/src/dhtproto/client/legacy/internal/registry/model/IDhtNodeRegistryInfo.d
index 5a6e0fea..ecbbfd44 100644
--- a/src/dhtproto/client/legacy/internal/registry/model/IDhtNodeRegistryInfo.d
+++ b/src/dhtproto/client/legacy/internal/registry/model/IDhtNodeRegistryInfo.d
@@ -122,7 +122,7 @@ public interface IDhtNodeRegistryInfo : INodeRegistryInfo
 
     **************************************************************************/
 
-    public int opApply ( int delegate ( ref IDhtNodeConnectionPoolInfo ) dg );
+    public int opApply ( scope int delegate ( ref IDhtNodeConnectionPoolInfo ) dg );
 
 
     /***************************************************************************
diff --git a/src/dhtproto/client/legacy/internal/request/params/RequestParams.d b/src/dhtproto/client/legacy/internal/request/params/RequestParams.d
index dd8553c8..2b54e650 100644
--- a/src/dhtproto/client/legacy/internal/request/params/RequestParams.d
+++ b/src/dhtproto/client/legacy/internal/request/params/RequestParams.d
@@ -173,7 +173,7 @@ public class RequestParams : IChannelRequestParams
 
     ***************************************************************************/
 
-    override protected void notify_ ( void delegate ( IRequestNotification ) info_dg )
+    override protected void notify_ ( scope void delegate ( IRequestNotification ) info_dg )
     {
         scope info = new RequestNotification(cast(DhtConst.Command.E)this.command,
             this.context);
diff --git a/src/dhttest/DhtClient.d b/src/dhttest/DhtClient.d
index f68a5d59..f5debcef 100644
--- a/src/dhttest/DhtClient.d
+++ b/src/dhttest/DhtClient.d
@@ -184,7 +184,7 @@ class DhtClient
     {
         this.log = Log.lookup("dhttest");
 
-        const max_connections = 2;
+        static immutable max_connections = 2;
         this.swarm_client = new SwarmClient(theScheduler.epoll, max_connections);
     }
 
@@ -550,7 +550,7 @@ class DhtClient
 
     public Listener startListen ( cstring channel )
     {
-        const hash_t key = 0xDEAD;
+        static immutable hash_t key = 0xDEAD;
 
         auto listener = new Listener;
 
diff --git a/src/dhttest/cases/Basic.d b/src/dhttest/cases/Basic.d
index a43c9470..107ffdbf 100644
--- a/src/dhttest/cases/Basic.d
+++ b/src/dhttest/cases/Basic.d
@@ -23,7 +23,7 @@ import ocean.transition;
 
 import dhttest.DhtTestCase;
 
-const PRIORITY = 100;
+static immutable PRIORITY = 100;
 
 /*******************************************************************************
 
diff --git a/src/dhttest/cases/BasicListen.d b/src/dhttest/cases/BasicListen.d
index 3ef6c6ef..efadfcf0 100644
--- a/src/dhttest/cases/BasicListen.d
+++ b/src/dhttest/cases/BasicListen.d
@@ -26,7 +26,7 @@ import ocean.core.Test;
 import ocean.io.select.fiber.SelectFiber;
 import ocean.io.select.client.FiberTimerEvent;
 
-const PRIORITY = 90;
+static immutable PRIORITY = 90;
 
 /*******************************************************************************
 
@@ -51,7 +51,7 @@ class ListenRemovedChannel : DhtTestCase
     override public void run ( )
     {
         auto listener = this.dht.startListen(this.test_channel);
-        const key = 0;
+        static immutable key = 0;
         this.dht.put(this.test_channel, key, "whatever"[]);
         listener.waitNextEvent();
         test(!listener.finished);
@@ -87,7 +87,7 @@ class ListenTrigger : DhtTestCase
     {
         auto listener = this.dht.startListen(this.test_channel);
 
-        const key = 5;
+        static immutable key = 5;
         this.dht.put(this.test_channel, key, "value"[]);
         listener.waitNextEvent();
         test!("==")(listener.data.length, 1);
diff --git a/src/dhttest/util/LocalStore.d b/src/dhttest/util/LocalStore.d
index 90da499a..acad90e4 100644
--- a/src/dhttest/util/LocalStore.d
+++ b/src/dhttest/util/LocalStore.d
@@ -54,7 +54,7 @@ struct LocalStore
 
     public void put ( hash_t key, cstring val )
     {
-        this.data[key] = val.dup;
+        (&this).data[key] = val.dup;
     }
 
     /***************************************************************************
@@ -68,7 +68,7 @@ struct LocalStore
 
     public void remove ( hash_t key )
     {
-        this.data.remove(key);
+        (&this).data.remove(key);
     }
 }
 
@@ -107,14 +107,14 @@ public struct LegacyVerifier
     public void verifyAgainstDht ( ref LocalStore local, DhtClient dht,
         cstring channel )
     {
-        this.local = &local;
-
-        this.verifyGetChannelSize(dht, channel);
-        this.verifyGetAll(dht, channel);
-        this.verifyGetAllFilter(dht, channel);
-        this.verifyGetAllKeys(dht, channel);
-        this.verifyExists(dht, channel);
-        this.verifyGet(dht, channel);
+        (&this).local = &local;
+
+        (&this).verifyGetChannelSize(dht, channel);
+        (&this).verifyGetAll(dht, channel);
+        (&this).verifyGetAllFilter(dht, channel);
+        (&this).verifyGetAllKeys(dht, channel);
+        (&this).verifyExists(dht, channel);
+        (&this).verifyGet(dht, channel);
     }
 
     /***************************************************************************
@@ -136,8 +136,8 @@ public struct LegacyVerifier
         ulong records, bytes;
         dht.getChannelSize(channel, records, bytes);
         log.trace("\tVerifying channel with GetChannelSize: local:{}, remote:{}",
-            this.local.data.length, records);
-        test!("==")(this.local.data.length, records);
+            (&this).local.data.length, records);
+        test!("==")((&this).local.data.length, records);
     }
 
     /***************************************************************************
@@ -158,13 +158,13 @@ public struct LegacyVerifier
     {
         auto remote = dht.getAll(channel);
         log.trace("\tVerifying channel with GetAll: local:{}, remote:{}",
-            this.local.data.length, remote.length);
-        test!("==")(this.local.data.length, remote.length);
+            (&this).local.data.length, remote.length);
+        test!("==")((&this).local.data.length, remote.length);
 
         foreach ( k, v; remote )
         {
-            test!("in")(k, this.local.data);
-            test!("==")(v, this.local.data[k]);
+            test!("in")(k, (&this).local.data);
+            test!("==")(v, (&this).local.data[k]);
         }
     }
 
@@ -186,10 +186,10 @@ public struct LegacyVerifier
 
     private void verifyGetAllFilter ( DhtClient dht, cstring channel )
     {
-        const filter = "0";
+        enum filter = "0";
 
         hash_t[] local;
-        foreach ( k, v; this.local.data )
+        foreach ( k, v; (&this).local.data )
         {
             if ( v.contains(filter) )
                 local ~= k;
@@ -203,7 +203,7 @@ public struct LegacyVerifier
         foreach ( k, v; remote )
         {
             test(local.contains(k));
-            test!("==")(v, this.local.data[k]);
+            test!("==")(v, (&this).local.data[k]);
         }
     }
 
@@ -225,12 +225,12 @@ public struct LegacyVerifier
     {
         auto remote = dht.getAllKeys(channel);
         log.trace("\tVerifying channel with GetAllKeys: local:{}, remote:{}",
-            this.local.data.length, remote.length);
-        test!("==")(this.local.data.length, remote.length);
+            (&this).local.data.length, remote.length);
+        test!("==")((&this).local.data.length, remote.length);
 
         foreach ( k; remote )
         {
-            test!("in")(k, this.local.data);
+            test!("in")(k, (&this).local.data);
         }
     }
 
@@ -251,7 +251,7 @@ public struct LegacyVerifier
     private void verifyExists ( DhtClient dht, cstring channel )
     {
         log.trace("\tVerifying channel with Exists");
-        foreach ( k, v; this.local.data )
+        foreach ( k, v; (&this).local.data )
         {
             auto exists = dht.exists(channel, k);
             test(exists);
@@ -275,7 +275,7 @@ public struct LegacyVerifier
     private void verifyGet ( DhtClient dht, cstring channel )
     {
         log.trace("\tVerifying channel with Get");
-        foreach ( k, v; this.local.data )
+        foreach ( k, v; (&this).local.data )
         {
             auto remote_v = dht.get(channel, k);
             test!("==")(remote_v, v);
diff --git a/src/dummydhtapp/main.d b/src/dummydhtapp/main.d
index c9f9856a..c2824a65 100644
--- a/src/dummydhtapp/main.d
+++ b/src/dummydhtapp/main.d
@@ -108,13 +108,13 @@ void main ( istring[] args )
     fiber = new SelectFiber(epoll, &handshakeAndRegister, 256 * 1024);
     event = new FiberSelectEvent(fiber);
 
-    void ping_handler ( cstring args, void delegate ( cstring
+    void ping_handler ( cstring args, scope void delegate ( cstring
         response ) send_response )
     {
         send_response("pong " ~ args);
     }
 
-    void reset_handler ( cstring args, void delegate ( cstring
+    void reset_handler ( cstring args, scope void delegate ( cstring
         response ) send_response )
     {
         send_response("ACK");
diff --git a/src/fakedht/ConnectionHandler.d b/src/fakedht/ConnectionHandler.d
index e44773a1..44d9cccd 100644
--- a/src/fakedht/ConnectionHandler.d
+++ b/src/fakedht/ConnectionHandler.d
@@ -223,7 +223,7 @@ public class DhtConnectionHandler :
 
     ***************************************************************************/
 
-    public this (void delegate(IConnectionHandler) finalize_dg,
+    public this (scope void delegate(IConnectionHandler) finalize_dg,
         ConnectionSetupParams setup )
     {
         super(finalize_dg, setup);
diff --git a/src/fakedht/DhtNode.d b/src/fakedht/DhtNode.d
index 436e8bc8..c1a19642 100644
--- a/src/fakedht/DhtNode.d
+++ b/src/fakedht/DhtNode.d
@@ -83,7 +83,7 @@ public class DhtNode
 
     public this ( DhtConst.NodeItem node_item, EpollSelectDispatcher epoll )
     {
-        const backlog = 20;
+        static immutable backlog = 20;
 
         auto params = new ConnectionSetupParams;
         params.epoll = epoll;
diff --git a/src/fakedht/Storage.d b/src/fakedht/Storage.d
index c8f92a71..4fd3f2f0 100644
--- a/src/fakedht/Storage.d
+++ b/src/fakedht/Storage.d
@@ -72,7 +72,7 @@ struct DHT
 
     public Channel get (cstring channel_name)
     {
-        auto channel = channel_name in this.channels;
+        auto channel = channel_name in (&this).channels;
         if (channel is null)
             return null;
         return *channel;
@@ -93,7 +93,7 @@ struct DHT
 
     public Channel getVerify ( cstring channel_name )
     {
-        auto channel = channel_name in this.channels;
+        auto channel = channel_name in (&this).channels;
         enforce!(MissingChannelException)(channel !is null, idup(channel_name));
         return *channel;
     }
@@ -112,11 +112,11 @@ struct DHT
 
     public Channel getCreate (cstring channel_name)
     {
-        auto channel = channel_name in this.channels;
+        auto channel = channel_name in (&this).channels;
         if (channel is null)
         {
-            this.channels[idup(channel_name)] = new Channel;
-            channel = channel_name in this.channels;
+            (&this).channels[idup(channel_name)] = new Channel;
+            channel = channel_name in (&this).channels;
         }
         return *channel;
     }
@@ -132,11 +132,11 @@ struct DHT
 
     public void remove (cstring channel_name)
     {
-        auto channel = this.get(channel_name);
+        auto channel = (&this).get(channel_name);
         if (channel !is null)
         {
             channel.listeners.trigger(DhtListener.Code.Finish, "");
-            this.channels.remove(idup(channel_name));
+            (&this).channels.remove(idup(channel_name));
         }
     }
 
@@ -148,10 +148,10 @@ struct DHT
 
     public void clear ( )
     {
-        auto names = this.channels.keys;
+        auto names = (&this).channels.keys;
         foreach (name; names)
         {
-            auto channel = this.getVerify(name);
+            auto channel = (&this).getVerify(name);
             channel.data = null;
         }
     }
@@ -167,7 +167,7 @@ struct DHT
 
     public void dropAllListeners ( )
     {
-        foreach (channel; this.channels)
+        foreach (channel; (&this).channels)
         {
             channel.listeners = channel.new Listeners;
         }
@@ -184,7 +184,7 @@ struct DHT
     {
         istring[] result;
 
-        foreach (key, value; this.channels)
+        foreach (key, value; (&this).channels)
             result ~= key;
 
         return result;
diff --git a/src/turtle/env/Dht.d b/src/turtle/env/Dht.d
index c062fc9d..17a3de60 100644
--- a/src/turtle/env/Dht.d
+++ b/src/turtle/env/Dht.d
@@ -137,7 +137,7 @@ public class Dht : Node!(DhtNode, "dht")
     unittest
     {
         struct NotVersioned { int x; }
-        struct Versioned { const StructVersion = 0; int x; }
+        struct Versioned { enum StructVersion = 0; int x; }
 
         // ensures compilation
         void stub ( )
@@ -350,7 +350,7 @@ public class Dht : Node!(DhtNode, "dht")
     ***************************************************************************/
 
     public void expectRecordCondition ( cstring channel, hash_t key,
-        bool delegate ( in void[] record ) dg,
+        scope bool delegate ( in void[] record ) dg,
         double timeout = 1.0, double check_interval = 0.05 )
     {
         char[Hash.HashDigits] str_key;
@@ -438,7 +438,7 @@ public class Dht : Node!(DhtNode, "dht")
     ***************************************************************************/
 
     private void waitForCondition ( double timeout, double check_interval,
-        bool delegate ( ) condition, lazy istring err_msg )
+        scope bool delegate ( ) condition, lazy istring err_msg )
     {
         auto total_wait = 0.0;
 
@@ -671,7 +671,7 @@ unittest
 {
     struct Something
     {
-        const StructVersion = 1;
+        enum StructVersion = 1;
         int a, b;
     }