diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 949b3b0..8e845f9 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -90,4 +90,20 @@
 of an SSH context (for example the patchset-created hook) don't know
 the server's web URL, unless this variable is configured.
 
+
+Debugging Hooks
+---------------
+
+After execution of a hook, its exit code and any output are logged at
+debug level. To make this visible in Gerrit's log file, debug logging
+must be enabled for `com.googlesource.gerrit.plugins.hooks.HookTask`.
+
+This can be done by editing the `log4j.properties` file (requires a
+Gerrit restart) or by setting the log level at runtime with the ssh
+command:
+
+---
+  ssh -p 29418 user@gerrit gerrit logging set-level DEBUG com.googlesource.gerrit.plugins.hooks.HookTask
+---
+
 [1]: ../../../Documentation/config-gerrit.html#gerrit.canonicalWebUrl