diff --git a/runtime/doc/testing.txt b/runtime/doc/testing.txt
index c5fa2e8..7fb24e6 100644
--- a/runtime/doc/testing.txt
+++ b/runtime/doc/testing.txt
@@ -52,6 +52,11 @@
 		startup has finished.
 
 
+test_clear_search_pat()				*test_clear_search_pat()*
+		Clears the last used search pattern (|/|) and the substitute
+		pattern (|:s|). This is useful for testing conditions where
+		these patterns are not set previously.
+
 test_feedinput({string})				*test_feedinput()*
 		Characters in {string} are queued for processing as if they
 		were typed by the user. This uses a low level input buffer.