-# deb http://deb.grml.org/ grml-stable main
-# deb-src http://deb.grml.org/ grml-stable main
-# deb http://deb.grml.org/ grml-testing main
-# deb-src http://deb.grml.org/ grml-testing main</pre>
+# deb [signed-by=/usr/share/keyrings/grml-archive-keyring.gpg] http://deb.grml.org/ grml-stable main
+# deb-src [signed-by=/usr/share/keyrings/grml-archive-keyring.gpg] http://deb.grml.org/ grml-stable main
+# deb [signed-by=/usr/share/keyrings/grml-archive-keyring.gpg] http://deb.grml.org/ grml-testing main
+# deb-src [signed-by=/usr/share/keyrings/grml-archive-keyring.gpg] http://deb.grml.org/ grml-testing main</pre>