diff --git a/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java b/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
index 0563f69..15b7936 100644
--- a/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
@@ -1394,7 +1394,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
                 break;
             case NULL:
                 opCode = REF_NULL;
-                type = options.useGC() ? ValueType.anyref : ValueType.externref;
+                type = options.useGC() ? ValueType.eqref : ValueType.externref;
                 break;
             default:
                 throw new Error( "Unknown operator: " + op );
diff --git a/src/de/inetsoftware/jwebassembly/binary/StructTypeEntry.java b/src/de/inetsoftware/jwebassembly/binary/StructTypeEntry.java
index c2c482b..3f48b6f 100644
--- a/src/de/inetsoftware/jwebassembly/binary/StructTypeEntry.java
+++ b/src/de/inetsoftware/jwebassembly/binary/StructTypeEntry.java
@@ -55,8 +55,8 @@ class StructTypeEntry extends TypeEntry {
     void writeSectionEntryDetails( WasmOutputStream stream ) throws IOException {
         stream.writeVaruint32( this.fields.size() );
         for( NamedStorageType field : this.fields ) {
-            stream.writeVarint( 1 ); // 0 - immutable; 1 - mutable 
             stream.writeRefValueType( field.getType() );
+            stream.writeVarint( 1 ); // 0 - immutable; 1 - mutable 
         }
     }
 
diff --git a/src/de/inetsoftware/jwebassembly/binary/WasmOutputStream.java b/src/de/inetsoftware/jwebassembly/binary/WasmOutputStream.java
index eebf7f9..5ccd80a 100644
--- a/src/de/inetsoftware/jwebassembly/binary/WasmOutputStream.java
+++ b/src/de/inetsoftware/jwebassembly/binary/WasmOutputStream.java
@@ -99,7 +99,7 @@ class WasmOutputStream extends LittleEndianOutputStream {
         if( type.isRefType() ) {
             if( options.useGC() ) {
                 //TODO writeValueType( ValueType.ref_type );
-                type = ValueType.anyref;
+                type = ValueType.eqref;
             } else {
                 type = ValueType.externref;
             }
diff --git a/src/de/inetsoftware/jwebassembly/module/TypeManager.java b/src/de/inetsoftware/jwebassembly/module/TypeManager.java
index cef9d0b..6c8e6a8 100644
--- a/src/de/inetsoftware/jwebassembly/module/TypeManager.java
+++ b/src/de/inetsoftware/jwebassembly/module/TypeManager.java
@@ -783,7 +783,7 @@ public class TypeManager {
         @Override
         public boolean isSubTypeOf( AnyType type ) {
             //TODO if type is StructType (class or interface)
-            return type == this || type == ValueType.externref || type == ValueType.anyref;
+            return type == this || type == ValueType.externref || type == ValueType.anyref || type == ValueType.eqref;
         }
 
         /**
diff --git a/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java b/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java
index 59f63c5..e1844ed 100644
--- a/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java
+++ b/src/de/inetsoftware/jwebassembly/module/WasmStructInstruction.java
@@ -203,7 +203,7 @@ class WasmStructInstruction extends WasmInstruction {
     AnyType getPushValueType() {
         switch( op ) {
             case NULL:
-                return options.useGC() ? ValueType.anyref : ValueType.externref;
+                return options.useGC() ? ValueType.eqref : ValueType.externref;
             case NEW:
             case NEW_DEFAULT:
             case CAST:
diff --git a/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java b/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java
index 349b840..e137895 100644
--- a/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java
@@ -316,7 +316,7 @@ public class TextModuleWriter extends ModuleWriter {
         if( !type.isRefType() ) {
             output.append( type.toString() );
         } else if( options.useGC() ) {
-            output.append( ValueType.anyref.toString() );
+            output.append( ValueType.eqref.toString() );
             //TODO output.append( "(optref " ).append( normalizeName( type.toString() ) ).append( ')' );
         } else {
             output.append( ValueType.externref.toString() );
@@ -859,7 +859,7 @@ public class TextModuleWriter extends ModuleWriter {
                 operation = "struct.set";
                 break;
             case NULL:
-                operation = options.useGC() ? "ref.null any" : "ref.null extern";
+                operation = options.useGC() ? "ref.null eq" : "ref.null extern";
                 type = null;
                 break;
             default:
diff --git a/src/de/inetsoftware/jwebassembly/wasm/ValueType.java b/src/de/inetsoftware/jwebassembly/wasm/ValueType.java
index 2292fae..1280b9e 100644
--- a/src/de/inetsoftware/jwebassembly/wasm/ValueType.java
+++ b/src/de/inetsoftware/jwebassembly/wasm/ValueType.java
@@ -24,12 +24,14 @@ public enum ValueType implements AnyType {
     f32(-0x03),
     f64(-0x04),
     v128(-0x05),
-    i8(-0x06), //TODO dummy value for https://github.com/WebAssembly/gc
-    i16(-0x07), //TODO dummy value for https://github.com/WebAssembly/gc
+    i8(-0x06),
+    i16(-0x07),
     funcref(-0x10),
     externref(-0x11),
     anyref(-0x12),
-    ref_type(-0x13 ), // 0x6D https://github.com/lars-t-hansen/moz-gc-experiments/blob/master/version2.md
+    eqref(-0x13),
+    optref(-0x14),
+    ref(-0x15),
     exnref(-0x18), // https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md
     func(-0x20),
     struct(-0x21),