diff --git a/doomsday/plugins/hexen/include/acscript.h b/doomsday/plugins/hexen/include/acscript.h
index 0697ea5235..b66a91f6ff 100644
--- a/doomsday/plugins/hexen/include/acscript.h
+++ b/doomsday/plugins/hexen/include/acscript.h
@@ -207,7 +207,7 @@ class ACScriptInterpreter
      */
     AutoStr *scriptDescription(int scriptNumber);
 
-    void writeWorldScriptData(de::Writer &to);
+    void writeWorldScriptData(de::Writer &to) const;
     void readWorldScriptData(de::Reader &from);
 
     void writeMapScriptData(MapStateWriter *msw);
@@ -233,7 +233,7 @@ class ACScriptInterpreter
         int scriptNumber; ///< On the target map.
         byte args[4];
 
-        void write(Writer *to) const;
+        void write(de::Writer &to) const;
         void read(de::Reader &from);
     };
 
diff --git a/doomsday/plugins/hexen/src/acscript.cpp b/doomsday/plugins/hexen/src/acscript.cpp
index 112f57a0ce..aaae6d4aad 100644
--- a/doomsday/plugins/hexen/src/acscript.cpp
+++ b/doomsday/plugins/hexen/src/acscript.cpp
@@ -467,17 +467,17 @@ void ACScriptInterpreter::scriptFinished(ACScript *script)
     Thinker_Remove(&script->thinker);
 }
 
-void ACScriptInterpreter::writeWorldScriptData(Writer &to)
+void ACScriptInterpreter::writeWorldScriptData(de::Writer &to) const
 {
-    byte ver = 4;
-    to << ver; // version byte
+    to << byte(4); // Version.
 
+    // Write the world-global variable namespace.
     for(int i = 0; i < MAX_ACS_WORLD_VARS; ++i)
     {
         to << worldVars[i];
     }
 
-    // Serialize the deferred task queue.
+    // Write the deferred task queue.
     to << _deferredTasksSize;
     for(int i = 0; i < _deferredTasksSize; ++i)
     {
@@ -489,12 +489,13 @@ void ACScriptInterpreter::readWorldScriptData(de::Reader &from)
 {
     byte ver; from >> ver;
 
+    // Read the world-global variable namespace.
     for(int i = 0; i < MAX_ACS_WORLD_VARS; ++i)
     {
         from >> worldVars[i];
     }
 
-    // Deserialize the deferred task queue.
+    // Read the deferred task queue.
     clearDeferredTasks();
     from >> _deferredTasksSize;
     if(_deferredTasksSize)