diff --git a/spa/plugins/filter-graph/plugin_builtin.c b/spa/plugins/filter-graph/plugin_builtin.c
index 1e4ae4e41..899212296 100644
--- a/spa/plugins/filter-graph/plugin_builtin.c
+++ b/spa/plugins/filter-graph/plugin_builtin.c
@@ -3114,8 +3114,11 @@ static void *pipe_instantiate(const struct spa_fga_plugin *plugin, const struct
 
 	do_exec(impl, command);
 
-	fcntl(impl->write_fd, F_SETFL, fcntl(impl->write_fd, F_GETFL) | O_NONBLOCK);
-	fcntl(impl->read_fd, F_SETFL, fcntl(impl->read_fd, F_GETFL) | O_NONBLOCK);
+	int flags;
+	if ((flags = fcntl(impl->write_fd, F_GETFL)) >= 0)
+		fcntl(impl->write_fd, F_SETFL, flags | O_NONBLOCK);
+	if ((flags = fcntl(impl->read_fd, F_GETFL)) >= 0)
+		fcntl(impl->read_fd, F_SETFL, flags | O_NONBLOCK);
 
 	return impl;
 }