diff --git a/src/Bytecode/Instruction/execute.c b/src/Bytecode/Instruction/execute.c
index 5f4c25d..fc86f12 100644
--- a/src/Bytecode/Instruction/execute.c
+++ b/src/Bytecode/Instruction/execute.c
@@ -782,6 +782,7 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
 
             for (GroundSize i = 0; i < function->args.count; i++) {
                 if (function->args.at[i].as.type.type != HEAP_GET(heap, instruction->args.at[i+1])->type.type) {
+                    printf("%d != %d\n", function->args.at[i].as.type.type, HEAP_GET(heap, instruction->args.at[i+1])->type.type);
                     Ground.Log.Error("incorrect type of argument for native function in Ground.Bytecode.Instruction.execute");
                     Ground.Flags.error = true;
                     return CONTINUE;
@@ -979,15 +980,15 @@ struct GroundExecutionResult _GroundBytecodeInstructionExecute(GroundBytecodeIns
         }
 
         for (size_t i = 0; i < argsSize; i++) {
-            enum GroundTypeType argTypeType = HEAP_GET(heap, instruction->args.at[i + 4])->as.CoreType;
-            switch (argTypeType) {
+            GroundBytecodeValue* argTypeVal = HEAP_GET(heap, instruction->args.at[i + 4]);
+            switch (argTypeVal->type.type) {
                 case GroundType_Struct: {
                     bf.args.at[i].as.type.type = GroundType_Object;
                     // TODO implement structs
                     break;
                 }
                 case GroundType_CoreType: {
-                    bf.args.at[i].as.type.type = HEAP_GET(heap, instruction->args.at[i + 4])->as.CoreType;
+                    bf.args.at[i].as.type.type = argTypeVal->as.CoreType;
                     break;
                 }
                 default: {
diff --git a/src/New/BytecodeValue.c b/src/New/BytecodeValue.c
index 0b075c5..1bf4a31 100644
--- a/src/New/BytecodeValue.c
+++ b/src/New/BytecodeValue.c
@@ -96,6 +96,10 @@ GroundBytecodeValue _GroundNewBytecodeValue(GroundValue value) {
             // TODO - convert to bytecode object 
             break;
         }
+        case GroundType_CoreType: {
+            bv.as.CoreType = value.as.CoreType;
+            break;
+        }
     } 
 
     return bv;