2 files changed, 3 insertions, 2 deletions
diff --git a/README.markdown b/README.markdown
index 429f653..54a83c6 100644
--- a/README.markdown
+++ b/README.markdown
@@ -3,7 +3,8 @@ Checkem
 
 Find duplicate files efficiently, using Perl on Unix-like operating systems,
 and maybe other ones too (untested). Requires only modules that have been in
-Perl core since 5.6.0 at the latest.
+Perl core since 5.7.3 at the latest. On earlier Perls, you will need to install
+`Digest`.
 
 Requires at least one directory argument:
 
diff --git a/checkem b/checkem
index da6d691..7afcdbb 100755
--- a/checkem
+++ b/checkem
@@ -18,7 +18,7 @@ use utf8;
 # Tolerate very old Perls
 use 5.006;
 
-# Import required modules
+# Import modules; Digest is the only one that wasn't in Perl 5.6 core
 use Carp;
 use Fcntl ':mode';
 use File::Find;