diff --git a/env.1 b/env.1
index 1c717df..bd6672b 100644
--- a/env.1
+++ b/env.1
@@ -29,6 +29,10 @@ Completely ignore the existing environment and execute
 only with each
 .Ar ( variable , value )
 tuple specified.
+.It Fl u Ar variable
+Unset
+.Ar variable
+in the environment.
 .El
 .Sh SEE ALSO
 .Xr printenv 1 ,