diff --git a/tools/websocket_to_posix_proxy/src/websocket_to_posix_proxy.c b/tools/websocket_to_posix_proxy/src/websocket_to_posix_proxy.c
index 6f9a10c23ad2d..776bcdad9b66d 100644
--- a/tools/websocket_to_posix_proxy/src/websocket_to_posix_proxy.c
+++ b/tools/websocket_to_posix_proxy/src/websocket_to_posix_proxy.c
@@ -1494,6 +1494,7 @@ void Getaddrinfo(int client_fd, uint8_t *data, uint64_t numBytes) {
   r->ret = ret;
   r->errno_ = errorCode;
   strncpy(r->ai_canonname, ai_canonname, MAX_NODE_LEN-1);
+  r->ai_canonname[MAX_NODE_LEN-1] = 0; // Null terminate output string if it truncated.
   r->addrCount = addrCount;
 
   struct addrinfo *ai = res;