diff --git a/src/Generator/Generators/QuickJS/QuickJSSources.cs b/src/Generator/Generators/QuickJS/QuickJSSources.cs
index 4ec2cf63..036ff7b7 100644
--- a/src/Generator/Generators/QuickJS/QuickJSSources.cs
+++ b/src/Generator/Generators/QuickJS/QuickJSSources.cs
@@ -598,7 +598,7 @@ namespace CppSharp.Generators.Cpp
             WriteLine("if (phase == 0)");
             WriteOpenBraceAndIndent();
             {
-                WriteLine($"JS_NewClassID(&{classId});");
+                WriteLine($"JS_NewClassID(JS_GetRuntime(ctx), &{classId});");
                 NewLine();
 
                 WriteLine($"JS_NewClass(JS_GetRuntime(ctx), {classId}, &{classDef});");
diff --git a/src/Generator/Generators/QuickJS/Runtime/CppSharp_QuickJS.h b/src/Generator/Generators/QuickJS/Runtime/CppSharp_QuickJS.h
index 0860be71..fb897ae8 100644
--- a/src/Generator/Generators/QuickJS/Runtime/CppSharp_QuickJS.h
+++ b/src/Generator/Generators/QuickJS/Runtime/CppSharp_QuickJS.h
@@ -174,9 +174,12 @@ static JSValue JS_Interop_CleanupObject(JSValue obj, JS_Interop_InstanceKind kin
     switch (kind)
     {
     case JS_INTEROP_INSTANCE_SIGNAL_CONTEXT:
-        JS_Interop_ClassData* data = (JS_Interop_ClassData*) JS_GetOpaque(obj, 0);
-        JS_Interop_FreeEventMap(data->ctx, &data->events);
-        js_free(data->ctx, data);
+        JS_Interop_ClassData* data = (JS_Interop_ClassData*) JS_GetOpaque(obj, JS_GetClassID(obj));
+        if (data)
+        {
+            JS_Interop_FreeEventMap(data->ctx, &data->events);
+            js_free(data->ctx, data);
+        }
     }
 
     return JS_UNDEFINED;
diff --git a/src/Generator/Generators/QuickJS/Runtime/Signal.cpp b/src/Generator/Generators/QuickJS/Runtime/Signal.cpp
index 79059df5..96be089b 100644
--- a/src/Generator/Generators/QuickJS/Runtime/Signal.cpp
+++ b/src/Generator/Generators/QuickJS/Runtime/Signal.cpp
@@ -179,7 +179,7 @@ static void register_class__Signal(JSContext *ctx, JSModuleDef *m, bool set, int
 
     if (phase == 0)
     {
-        JS_NewClassID(&classId__Signal);
+        JS_NewClassID(JS_GetRuntime(ctx), &classId__Signal);
 
         JS_NewClass(JS_GetRuntime(ctx), classId__Signal, &classDef__Signal);