diff --git a/os/streams.c b/os/streams.c
index 0eae5ec9d..4142f43f9 100644
--- a/os/streams.c
+++ b/os/streams.c
@@ -1166,7 +1166,7 @@ static Int
       Yap_CheckStream(ARG1, Input_Stream_f | Output_Stream_f | Append_Stream_f,
                       "set_stream_position/2");
   if (sno < 0) {
-    return (FALSE);
+    return false;
   }
   tin = Deref(ARG2);
   if (IsVarTerm(tin)) {