diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index d315b5365..3279ddf06 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -2067,6 +2067,8 @@ The following methods are defined for all [dictionaries](Syntax.md#dictionaries)
   fallback value given as the second argument. If a single argument
   was given and the key was not found, causes a fatal error
 
+- `keys()`: returns an array of keys in the dictionary
+
 You can also iterate over dictionaries with the [`foreach`
 statement](Syntax.md#foreach-statements).