diff --git a/include/ac/socket.h b/include/ac/socket.h
index 4f2ed14812..f7534b9e32 100644
--- a/include/ac/socket.h
+++ b/include/ac/socket.h
@@ -23,8 +23,7 @@
 
 #ifdef HAVE_POLL_H
 #include <poll.h>
-#endif
-#ifdef HAVE_SYS_POLL_H
+#elif defined(HAVE_SYS_POLL_H)
 #include <sys/poll.h>
 #endif