diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index 183f0eb9304cd268142bee167db57ec637468636..e186d6368371d53942233b5760fb886f3407fbd4 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -95,6 +95,8 @@ static void pipe_destroy(grpc_wakeup_fd* fd_info) {
 
 static int pipe_check_availability(void) {
   grpc_wakeup_fd fd;
+  fd.read_fd = fd.write_fd = -1;
+
   if (pipe_init(&fd) == GRPC_ERROR_NONE) {
     pipe_destroy(&fd);
     return 1;