diff --git a/doc/configuration.txt b/doc/configuration.txt
index 73d694c60..05ca6db14 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -631,6 +631,7 @@ The following keywords are supported in the "global" section :
    - wurfl-cache-size
 
  * Performance tuning
+   - busy-polling
    - max-spread-checks
    - maxconn
    - maxconnrate