diff --git a/ext/session/mod_user_class.c b/ext/session/mod_user_class.c
index a6bd69c91a07..d306842d0b9a 100644
--- a/ext/session/mod_user_class.c
+++ b/ext/session/mod_user_class.c
@@ -149,6 +149,12 @@ PHP_METHOD(SessionHandler, create_sid)
 	PS_SANITY_CHECK;
 
 	id = PS(default_mod)->s_create_sid(&PS(mod_data));
+	if (!id) {
+		if (!EG(exception)) {
+			zend_throw_error(NULL, "Failed to create session ID: %s", PS(default_mod)->s_name);
+		}
+		RETURN_THROWS();
+	}
 
 	RETURN_STR(id);
 }