diff --git a/IDEHelper/Compiler/BfExprEvaluator.cpp b/IDEHelper/Compiler/BfExprEvaluator.cpp
index 640391b4..de8eed6f 100644
--- a/IDEHelper/Compiler/BfExprEvaluator.cpp
+++ b/IDEHelper/Compiler/BfExprEvaluator.cpp
@@ -18134,7 +18134,9 @@ void BfExprEvaluator::PerformAssignment(BfAssignmentExpression* assignExpr, bool
 				auto argValue = ResolveArgValue(mIndexerValues[paramIdx], wantType);
 				if (refNode == NULL)
 					refNode = mPropSrc;
-				auto val = mModule->Cast(refNode, argValue, wantType);
+				BfTypedValue val;
+				if (argValue)
+					val = mModule->Cast(refNode, argValue, wantType);
 				if (!val)
 				{
 					mPropDef = NULL;