diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 062ccc3..602d909 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -3273,6 +3273,10 @@
 		is applied to filter the results.  Otherwise all the matches
 		are returned. The 'wildignorecase' option always applies.
 
+		If the 'wildoptions' option contains 'fuzzy', then fuzzy
+		matching is used to get the completion matches. Otherwise
+		regular expression matching is used.
+
 		If {type} is "cmdline", then the |cmdline-completion| result is
 		returned.  For example, to complete the possible values after
 		a ":call" command: >