diff --git a/src/core/iomgr/endpoint_pair_windows.c b/src/core/iomgr/endpoint_pair_windows.c
index d78b6ea957e35b0441a014e62ca9f716b6cd522c..58960b6028ae559b8e413d99276d2a554e538811 100644
--- a/src/core/iomgr/endpoint_pair_windows.c
+++ b/src/core/iomgr/endpoint_pair_windows.c
@@ -50,7 +50,7 @@ static void create_sockets(SOCKET sv[2]) {
   SOCKET lst_sock = INVALID_SOCKET;
   SOCKET cli_sock = INVALID_SOCKET;
   SOCKADDR_IN addr;
-  int addr_len;
+  int addr_len = sizeof(addr);
 
   lst_sock = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);
   GPR_ASSERT(lst_sock != INVALID_SOCKET);