diff --git a/bin/df/df.1 b/bin/df/df.1
index d3b0b082250..ceb1bb45bab 100644
--- a/bin/df/df.1
+++ b/bin/df/df.1
@@ -117,7 +117,7 @@ option and any
 .Ev BLOCKSIZE
 specification from the environment.
 .It Fl l
-Select locally-mounted file system for display.
+Select a locally-mounted file system for display.
 If used in combination with the
 .Fl t Ar type
 option, file system types will be added or excluded according to the