diff --git a/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java b/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
index 1f94744..a9c45cc 100644
--- a/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
+++ b/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
@@ -576,15 +576,23 @@ class JavaMethodWasmCodeBuilder extends WasmCodeBuilder {
                         addStructInstruction( StructOperator.SET, ref.getClassName(), new NamedStorageType( ref, getTypeManager() ), codePos, lineNumber );
                         break;
                     case 182: // invokevirtual
-                        idx = byteCode.readUnsignedShort();
-                        ref = (ConstantRef)constantPool.get( idx );
-                        addCallVirtualInstruction( new FunctionName( ref ), codePos, lineNumber );
-                        break;
                     case 183: // invokespecial, invoke a constructor
                     case 184: // invokestatic
                         idx = byteCode.readUnsignedShort();
                         ref = (ConstantRef)constantPool.get( idx );
-                        addCallInstruction( new FunctionName( ref ), codePos, lineNumber );
+                        FunctionName funcName = new FunctionName( ref );
+                        switch( op ) {
+                            case 182:
+                                addCallVirtualInstruction( funcName, codePos, lineNumber );
+                                break;
+                            case 183:
+                                getTypeManager().valueOf( funcName.className ); // TODO pass this as first parameter
+                                addCallInstruction( funcName, codePos, lineNumber );
+                                break;
+                            case 184:
+                                addCallInstruction( funcName, codePos, lineNumber );
+                                break;
+                        }
                         break;
                     //TODO case 185: // invokeinterface
                     //TODO case 186: // invokedynamic
diff --git a/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java b/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java
index 8754c1e..0126deb 100644
--- a/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java
+++ b/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java
@@ -180,6 +180,7 @@ public class ModuleGenerator {
             }
 
             if( functions.needToScan( next ) ) { // function was not found
+                // search if there is a super class with the same signature
                 ClassFile superClassFile = classFile;
                 while( superClassFile != null ) {
                     MethodInfo method = superClassFile.getMethod( next.methodName, next.signature );
@@ -187,7 +188,7 @@ public class ModuleGenerator {
                         FunctionName name = new FunctionName( method );
                         functions.markAsNeeded( name );
                         functions.setAlias( next, name );
-                        continue NEXT;
+                        continue NEXT; // we have found a super method
                     }
                     ConstantClass superClass = superClassFile.getSuperClass();
                     superClassFile = superClass == null ? null : ClassFile.get( superClass.getName(), libraries );
@@ -196,6 +197,8 @@ public class ModuleGenerator {
             }
         }
         functions.prepareFinish();
+
+        types.prepareFinish();
     }
 
     /**
diff --git a/src/de/inetsoftware/jwebassembly/module/TypeManager.java b/src/de/inetsoftware/jwebassembly/module/TypeManager.java
index f26a63d..35d08da 100644
--- a/src/de/inetsoftware/jwebassembly/module/TypeManager.java
+++ b/src/de/inetsoftware/jwebassembly/module/TypeManager.java
@@ -17,6 +17,7 @@
 package de.inetsoftware.jwebassembly.module;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -33,7 +34,15 @@ import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
  */
 public class TypeManager {
 
-    private final Map<String, StructType> map = new LinkedHashMap<>();
+    private Map<String, StructType> map = new LinkedHashMap<>();
+
+
+    /**
+     * Finish the prepare. Now no new function should be added. 
+     */
+    public void prepareFinish() {
+        map = Collections.unmodifiableMap( map );
+    }
 
     /**
      * Use the type in the output.