diff --git a/lib/gitlab/gitaly_client.rb b/lib/gitlab/gitaly_client.rb
index bcdf1b1faa89c40ab4cbf904ed474a38fc84f1a4..c69676a1dac5e6130ef9e02d96f76c14c8d278d8 100644
--- a/lib/gitlab/gitaly_client.rb
+++ b/lib/gitlab/gitaly_client.rb
@@ -15,7 +15,7 @@ module Gitlab
         end
 
         unless URI(address).scheme.in?(%w(tcp unix))
-          raise "Unsupported Gitaly address: #{address.inspect}"
+          raise "Unsupported Gitaly address: #{address.inspect} does not use URL scheme 'tcp' or 'unix'"
         end
 
         @addresses[name] = address