diff --git a/lib/Kernel.cs b/lib/Kernel.cs
index 9ec8a2ed..99620323 100644
--- a/lib/Kernel.cs
+++ b/lib/Kernel.cs
@@ -500,7 +500,7 @@ public List<DynMetaObject> superclasses
                         k.subclasses.Remove(wr_this);
         }
 
-        private void Invalidate() {
+        public void Invalidate() {
             if (mro == null)
                 return;
             List<DynMetaObject> notify = new List<DynMetaObject>();
@@ -547,7 +547,6 @@ public List<DynMetaObject> superclasses
 
         public void AddMethod(string name, IP6 code) {
             local[name] = code;
-            Invalidate();
         }
 
         public void AddPrivateMethod(string name, IP6 code) {
@@ -1069,6 +1068,7 @@ public class Kernel {
                 n.AddPrivateMethod(kv.Key, kv.Value);
             foreach (KeyValuePair<string, IP6> kv in role.local)
                 n.AddMethod(kv.Key, kv.Value);
+            n.Invalidate();
             if (role.multiregex != null)
                 foreach (KeyValuePair<string, List<DynObject>> kv
                         in role.multiregex)
@@ -1170,6 +1170,7 @@ class ExitRunloopException : Exception { }
             SubMO.OnInvoke = new DynMetaObject.InvokeHandler(SubInvoke);
             SubMO.FillProtoClass(new string[] { "outer", "info" });
             SubMO.AddMethod("INVOKE", MakeSub(SubInvokeSubSI, null));
+            SubMO.Invalidate();
 
             ScalarMO = new DynMetaObject("Scalar");
             ScalarMO.FillProtoClass(new string[] { "value" });
diff --git a/src/CLRTypes.pm b/src/CLRTypes.pm
index 1d02cc67..686c84b7 100644
--- a/src/CLRTypes.pm
+++ b/src/CLRTypes.pm
@@ -27,6 +27,7 @@ my %typedata = (
           HasMRO       => [m => 'Boolean'],
           AddMultiRegex=> [m => 'Void'],
           AddMethod    => [m => 'Void'],
+          Invalidate   => [m => 'Void'],
           AddPrivateMethod => [m => 'Void'],
           GetPrivateMethod => [m => 'IP6'],
           typeObject   => [f => 'IP6'],
diff --git a/src/CSharpBackend.pm b/src/CSharpBackend.pm
index c263a67e..409adece 100644
--- a/src/CSharpBackend.pm
+++ b/src/CSharpBackend.pm
@@ -284,6 +284,7 @@ sub pkg3 {
             CgOp::clr_string($m->name),
             CgOp::rawsget($unit->deref($m->body)->{peer}{ps}));
     }
+    push @thaw, CgOp::rawcall(CgOp::rawsget($p), 'Invalidate');
     for my $k (sort keys %{ $_->multi_regex_lists }) {
         for my $b (@{ $_->multi_regex_lists->{$k} }) {
             push @thaw, CgOp::rawcall(CgOp::rawsget($p), 'AddMultiRegex',
@@ -446,6 +447,7 @@ sub codegen_sub {
                 CgOp::clr_string($m->[0]),
                 CgOp::fetch(CgOp::scopedlex($m->[1])));
         }
+        push @build, CgOp::rawcall(CgOp::letvar('!mo'), 'Invalidate');
         for my $k (sort keys %{ $obj->multi_regex_lists }) {
             for my $b (@{ $obj->multi_regex_lists->{$k} }) {
                 push @build, CgOp::rawcall(CgOp::letvar('!mo'),