diff --git a/src/cmd/smlrc/cgmips.c b/src/cmd/smlrc/cgmips.c
index 73ea5d9..2cfde75 100644
--- a/src/cmd/smlrc/cgmips.c
+++ b/src/cmd/smlrc/cgmips.c
@@ -541,7 +541,7 @@ void GenUpdateFrameSize(void)
 STATIC
 void GenFxnProlog(void)
 {
-  if (CurFxnParamCntMax)
+  if (CurFxnParamCntMin && CurFxnParamCntMax)
   {
     int i, cnt = CurFxnParamCntMax;
     if (cnt > 4)