diff --git a/src/cmd/5c/swt.c b/src/cmd/5c/swt.c
index d45aabc5e6..431f048173 100644
--- a/src/cmd/5c/swt.c
+++ b/src/cmd/5c/swt.c
@@ -665,7 +665,9 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 
 	case Aarg2:	/* width of a parameter */
 		o += t->width;
-		w = SZ_LONG;
+		w = t->width;
+		if(w > SZ_LONG)
+			w = SZ_LONG;
 		break;
 
 	case Aaut3:	/* total align of automatic */