diff --git a/src/basic/basic_operators/oper_add.s b/src/basic/basic_operators/oper_add.s
index 52124a25..e663af97 100644
--- a/src/basic/basic_operators/oper_add.s
+++ b/src/basic/basic_operators/oper_add.s
@@ -9,8 +9,8 @@ oper_add:
 	// First check whether arguments match and then choose the variant
 
 	pla
-	cmp VALTYP
-	bne_16 do_TYPE_MISMATCH_error
+	eor VALTYP
+	bmi_16 do_TYPE_MISMATCH_error
 
 	lda VALTYP
 	bmi oper_add_strings