diff --git a/src/cc65/typecmp.c b/src/cc65/typecmp.c
index 24d9a385f..f179bff14 100644
--- a/src/cc65/typecmp.c
+++ b/src/cc65/typecmp.c
@@ -203,8 +203,8 @@ static void DoCompare (const Type* lhs, const Type* rhs, typecmp_t* Result)
         if ((IsTypeEnum (lhs) || IsTypeEnum (rhs))) {
 
             /* Compare the tag types */
-            Sym1 = GetESUSymEntry (lhs);
-            Sym2 = GetESUSymEntry (rhs);
+            Sym1 = IsTypeEnum (lhs) ? GetESUSymEntry (lhs) : 0;
+            Sym2 = IsTypeEnum (rhs) ? GetESUSymEntry (rhs) : 0;
 
             if (Sym1 != Sym2) {
                 if (Sym1 == 0 || Sym2 == 0) {