diff --git a/src/thingdef/thingdef_exp.h b/src/thingdef/thingdef_exp.h
index 691d4b8723..6dd11a681b 100644
--- a/src/thingdef/thingdef_exp.h
+++ b/src/thingdef/thingdef_exp.h
@@ -913,12 +913,12 @@ public:
 
 class FxClassTypeCast : public FxExpression
 {
-	const PClass *desttype;
+	PClass *desttype;
 	FxExpression *basex;
 
 public:
 
-	FxClassTypeCast(const PClass *dtype, FxExpression *x);
+	FxClassTypeCast(PClass *dtype, FxExpression *x);
 	~FxClassTypeCast();
 	FxExpression *Resolve(FCompileContext&);
 	ExpEmit Emit(VMFunctionBuilder *build);
diff --git a/src/thingdef/thingdef_expression.cpp b/src/thingdef/thingdef_expression.cpp
index f4c2b1f608..9124071e57 100644
--- a/src/thingdef/thingdef_expression.cpp
+++ b/src/thingdef/thingdef_expression.cpp
@@ -3503,7 +3503,7 @@ ExpEmit FxReturnStatement::Emit(VMFunctionBuilder *build, bool tailcall)
 //
 //==========================================================================
 
-FxClassTypeCast::FxClassTypeCast(const PClass *dtype, FxExpression *x)
+FxClassTypeCast::FxClassTypeCast(PClass *dtype, FxExpression *x)
 : FxExpression(x->ScriptPosition)
 {
 	desttype = dtype;
@@ -3542,11 +3542,11 @@ FxExpression *FxClassTypeCast::Resolve(FCompileContext &ctx)
 	if (basex->isConstant())
 	{
 		FName clsname = static_cast<FxConstant *>(basex)->GetValue().GetName();
-		const PClass *cls = NULL;
+		PClass *cls = NULL;
 
 		if (clsname != NAME_None)
 		{
-			cls = PClass::FindClass(clsname);
+			cls = desttype->FindClassTentative(clsname);
 			if (cls == NULL)
 			{
 				/* lax */