diff --git a/src/openvpn/mtu.c b/src/openvpn/mtu.c
index 66f81a6..9e152df 100644
--- a/src/openvpn/mtu.c
+++ b/src/openvpn/mtu.c
@@ -280,15 +280,9 @@
     struct timeval tv;
 };
 
-#if defined(__GNUC__) || defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wconversion"
-#endif
-
 const char *
 format_extended_socket_error(int fd, int *mtu, struct gc_arena *gc)
 {
-    int res;
     struct probehdr rcvbuf;
     struct iovec iov;
     struct msghdr msg;
@@ -313,7 +307,7 @@
         msg.msg_control = cbuf;
         msg.msg_controllen = 256; /* size of cbuf */
 
-        res = recvmsg(fd, &msg, MSG_ERRQUEUE);
+        ssize_t res = recvmsg(fd, &msg, MSG_ERRQUEUE);
         if (res < 0)
         {
             goto exit;
@@ -394,10 +388,6 @@
     return BSTR(&out);
 }
 
-#if defined(__GNUC__) || defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
-
 void
 set_sock_extended_error_passing(int sd, sa_family_t proto_af)
 {