diff --git a/lib/hostip.c b/lib/hostip.c
index 0ef806b72..4acf1217e 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -76,8 +76,8 @@
 /* The last #include file should be: */
 #include "memdebug.h"
 
-#if defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP) \
-    && !defined(USE_ARES)
+#if defined(CURLRES_SYNCH) && \
+    defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP)
 /* alarm-based timeouts can only be used with all the dependencies satisfied */
 #define USE_ALARM_TIMEOUT
 #endif
diff --git a/lib/url.c b/lib/url.c
index 12e7e3639..9f7cd0ac5 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -2489,11 +2489,12 @@ static void conn_free(struct connectdata *conn)
   Curl_llist_destroy(conn->done_pipe, NULL);
 
   /* possible left-overs from the async name resolvers */
-#if defined(USE_ARES)
+#if defined(CURLRES_ASYNCH)
   Curl_safefree(conn->async.hostname);
   Curl_safefree(conn->async.os_specific);
-#elif defined(CURLRES_THREADED)
+#if defined(CURLRES_THREADED)
   Curl_destroy_thread_data(&conn->async);
+#endif
 #endif
 
   Curl_free_ssl_config(&conn->ssl_config);
diff --git a/lib/version.c b/lib/version.c
index 03131e988..ec57885e9 100644
--- a/lib/version.c
+++ b/lib/version.c
@@ -217,7 +217,7 @@ static curl_version_info_data version_info = {
 #ifdef CURLDEBUG
   | CURL_VERSION_CURLDEBUG
 #endif
-#ifdef USE_ARES
+#ifdef CURLRES_ASYNCH
   | CURL_VERSION_ASYNCHDNS
 #endif
 #ifdef HAVE_SPNEGO