diff --git a/tests/data/test503 b/tests/data/test503
index b9f093f35..2189054e9 100644
--- a/tests/data/test503
+++ b/tests/data/test503
@@ -34,7 +34,7 @@ lib503
 simple multi http:// through proxytunnel with authentication info
  </name>
  <command>
-http://%HOSTIP:%HTTPSPORT/503 localhost:%HTTPPORT
+http://%HOSTIP:%HTTPSPORT/503 127.0.0.1:%HTTPPORT
 </command>
 <file name="log/test503.txt">
 foo
diff --git a/tests/data/test504 b/tests/data/test504
index f2a864123..32cff5f71 100644
--- a/tests/data/test504
+++ b/tests/data/test504
@@ -16,7 +16,7 @@ lib504
 simple multi through local proxy without listener
  </name>
  <command>
-http://%HOSTIP:%HTTPSPORT/504 localhost:55555
+http://%HOSTIP:%HTTPSPORT/504 127.0.0.1:55555
 </command>
 </client>
 
diff --git a/tests/data/test509 b/tests/data/test509
index 70ce7c183..06f3aab4b 100644
--- a/tests/data/test509
+++ b/tests/data/test509
@@ -30,7 +30,7 @@ lib509
 simple HTTPS GET and URL redirect in certificate
  </name>
  <command>
-https://localhost:%HTTPSPORT/dvcs %HTTPSPORT
+https://127.0.0.1:%HTTPSPORT/dvcs %HTTPSPORT
 </command>
 </client>
 
@@ -42,7 +42,7 @@ https://localhost:%HTTPSPORT/dvcs %HTTPSPORT
 </strip>
 <protocol>
 GET /509 HTTP/1.1
-Host: localhost:%HTTPSPORT
+Host: 127.0.0.1:%HTTPSPORT
 Pragma: no-cache
 Accept: */*
 
diff --git a/tests/libtest/lib509.c b/tests/libtest/lib509.c
index 9e535e9b6..d20c31524 100644
--- a/tests/libtest/lib509.c
+++ b/tests/libtest/lib509.c
@@ -121,7 +121,7 @@ static int ssl_app_verify_callback(X509_STORE_CTX *ctx, void *arg)
            URL in the cert uses a static one. We thus need to create a new
            URL that uses the currently requested port number which may not
            be the one this URL uses! */
-        sprintf(newurl, "https://localhost:%d/509", portnum);
+        sprintf(newurl, "https://127.0.0.1:%d/509", portnum);
         fprintf(stderr, "But *really* Setting URL <%s>\n", newurl);
 
         curl_easy_setopt(p->curl, CURLOPT_URL, newurl);