diff --git a/plugins/input/postgis/connection.hpp b/plugins/input/postgis/connection.hpp
index 1ba568a969..a774a9b465 100644
--- a/plugins/input/postgis/connection.hpp
+++ b/plugins/input/postgis/connection.hpp
@@ -70,6 +70,7 @@ class Connection
             {
                 s << "unable to connect to postgres server";
             }
+            s << "\n" << connection_str;
             throw mapnik::datasource_exception( s.str() );
         }
     }