diff --git a/tcg/optimize.c b/tcg/optimize.c
index de1abd9cc3..5fa4d7285d 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1730,6 +1730,7 @@ static bool fold_setcond(OptContext *ctx, TCGOp *op)
     }
 
     ctx->z_mask = 1;
+    ctx->s_mask = smask_from_zmask(1);
     return false;
 }
 
@@ -1802,6 +1803,7 @@ static bool fold_setcond2(OptContext *ctx, TCGOp *op)
     }
 
     ctx->z_mask = 1;
+    ctx->s_mask = smask_from_zmask(1);
     return false;
 
  do_setcond_const: