diff --git a/acinclude.m4 b/acinclude.m4
index 8730a8375..439961f5d 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -64,7 +64,7 @@ dnl the code was bad, try a different program now, test 3
 ],[
 /* ioctlsocket source code */
  int socket;
- int flags = ioctlsocket(socket, FIONBIO, &flags);
+ unsigned long flags = ioctlsocket(socket, FIONBIO, &flags);
 ],[
 dnl ioctlsocket test was good
 nonblock="ioctlsocket"
diff --git a/lib/connect.c b/lib/connect.c
index 0d42ca14d..b58a8be5d 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -147,7 +147,7 @@ int Curl_nonblock(curl_socket_t sockfd,    /* operate on this */
 
 #ifdef HAVE_IOCTLSOCKET
   /* Windows? */
-  int flags;
+  unsigned long flags;
   flags = nonblock;
   return ioctlsocket(sockfd, FIONBIO, &flags);
 #define SETBLOCK 3