diff --git a/acinclude.m4 b/acinclude.m4
index a7a84b4448..63183c751d 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -372,7 +372,7 @@ dnl the code was bad, try a different program now, test 3
 #endif
 ],[
 /* ioctlsocket source code */
- int socket;
+ SOCKET socket;
  unsigned long flags = ioctlsocket(socket, FIONBIO, &flags);
 ],[
 dnl ioctlsocket test was good
diff --git a/ares/acinclude.m4 b/ares/acinclude.m4
index a6cd87a9ac..de7f250796 100644
--- a/ares/acinclude.m4
+++ b/ares/acinclude.m4
@@ -372,7 +372,7 @@ dnl the code was bad, try a different program now, test 3
 #endif
 ],[
 /* ioctlsocket source code */
- int socket;
+ SOCKET socket;
  unsigned long flags = ioctlsocket(socket, FIONBIO, &flags);
 ],[
 dnl ioctlsocket test was good