diff --git a/mandel.s b/mandel.s
index 4ab6c19..04edec5 100644
--- a/mandel.s
+++ b/mandel.s
@@ -320,7 +320,7 @@ viewport_oy:
 
 ; 38 cycles
 .macro add32 dest, arg1, arg2
-    add 4, dest, arg2, dest
+    add 4, dest, arg1, arg2
 .endmacro
 
 ; 8 cycles