diff --git a/acme/simple_http_challenge.go b/acme/simple_http_challenge.go
index cab45f11..cf6ddafb 100644
--- a/acme/simple_http_challenge.go
+++ b/acme/simple_http_challenge.go
@@ -126,7 +126,11 @@ func (s *simpleHTTPChallenge) startHTTPSServer(domain string, token string) (net
 
 	tlsListener, err := tls.Listen("tcp", domain+port, tlsConf)
 	if err != nil {
-		return nil, err
+		// if the domain:port bind failed, fall back to :port bind and try that instead.
+		tlsListener, err = tls.Listen("tcp", port, tlsConf)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	jsonBytes, err := json.Marshal(challenge{Type: "simpleHttp", Token: token, TLS: true})
diff --git a/acme/simple_http_challenge_test.go b/acme/simple_http_challenge_test.go
index 5c0d460e..95924d92 100644
--- a/acme/simple_http_challenge_test.go
+++ b/acme/simple_http_challenge_test.go
@@ -24,9 +24,9 @@ func TestSimpleHTTPNonRootBind(t *testing.T) {
 	if err := solver.Solve(clientChallenge, "127.0.0.1"); err == nil {
 		t.Error("BIND: Expected Solve to return an error but the error was nil.")
 	} else {
-		expectedError := "Could not start HTTPS server for challenge -> listen tcp 127.0.0.1:443: bind: permission denied"
+		expectedError := "Could not start HTTPS server for challenge -> listen tcp :443: bind: permission denied"
 		if err.Error() != expectedError {
-			t.Errorf("Expected error %s but instead got %s", expectedError, err.Error())
+			t.Errorf("Expected error \"%s\" but instead got \"%s\"", expectedError, err.Error())
 		}
 	}
 }