diff --git a/doc/grep.in.1 b/doc/grep.in.1
index 5a1e3ea..3f633ea 100644
--- a/doc/grep.in.1
+++ b/doc/grep.in.1
@@ -478,6 +478,7 @@ Search only files whose base name matches
 .BR \-r ", " \-\^\-recursive
 Read all files under each directory, recursively,
 following symbolic links only if they are on the command line.
+Note that if no file operand is given, grep searches the working directory.
 This is equivalent to the
 .B "\-d recurse"
 option.
diff --git a/doc/grep.texi b/doc/grep.texi
index da9a1be..63016bd 100644
--- a/doc/grep.texi
+++ b/doc/grep.texi
@@ -698,6 +698,7 @@ For each directory operand,
 read and process all files in that directory, recursively.
 Follow symbolic links on the command line, but skip symlinks
 that are encountered recursively.
+Note that if no file operand is given, grep searches the working directory.
 This is the same as the @samp{--directories=recurse} option.
 
 @item -R