diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index c6c7d8e..c4feed1 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -352,8 +352,8 @@
 {
 	PyStdPrinter_Object *self;
 
-	if (fd != fileno(stdout) && fd != fileno(stderr)) {
-		PyErr_BadInternalCall();
+	if ((fd != fileno(stdout) && fd != fileno(stderr)) || fd < 0) {
+		/* not enough infrastructure for PyErr_BadInternalCall() */
 		return NULL;
 	}