diff --git a/doc/manual/expressions/builtins.xml b/doc/manual/expressions/builtins.xml
index e9baff659..8a18b7100 100644
--- a/doc/manual/expressions/builtins.xml
+++ b/doc/manual/expressions/builtins.xml
@@ -1163,6 +1163,19 @@ stdenv.mkDerivation (rec {
+ builtins.tryEval
+ e
+
+ Try to evaluate e.
+ Return a set containing the attributes success
+ (true if e evaluated
+ successfully, false if an error was thrown) and
+ value, equalling e
+ if successful and false otherwise.
+
+
+
+
builtins.typeOf
e