--- kdesu-5.5.0/src/kdesu_stub.c~	2015-02-13 16:53:30.000000000 +0300

+++ kdesu-5.5.0/src/kdesu_stub.c	2015-02-13 17:01:21.720000000 +0300

@@ -266,6 +266,7 @@ int main()

         exit(1);

     }

     xsetenv("HOME", pw->pw_dir);

+    xsetenv("USER", pw->pw_name);

     /* New user won't be able to connect it anyway. */

     unsetenv("DBUS_SESSION_BUS_ADDRESS");

@@ -308,6 +309,7 @@ int main()

             exit(1);

         }

         xsetenv("HOME", pw->pw_dir);

+        xsetenv("USER", pw->pw_name);

     }

     /* Handle display */