diff --git a/commands/check.py b/commands/check.py
index 173fe69..c5c108c 100644
--- a/commands/check.py
+++ b/commands/check.py
@@ -1,8 +1,9 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
            
-import os.path
+import os, os.path
 import filecmp
+import subprocess
 
 from metafile import Metafile, MalformedMetafileError
 
@@ -23,9 +24,9 @@ def init(parser):
                               "added files" )
     
     parser.add_argument( "-d", "--diff",
-                         type=str,
+                         action="store_true",
                          help="Print the diff between the saved and the new " \
-                              "file/directory" )
+                              "files" )
 
 
 # -----------------------------------------------------------------------------
@@ -33,6 +34,11 @@ def run(args, persoconf, logger):
 
     logger.debug("Starting 'check' command")
 
+    difftool = None
+    if args.diff:
+        difftool = os.environ.get('DIFFTOOL', 'vimdiff')
+        logger.info("Selecting %s as diff tool" % difftool)
+
     # app == None => check all apps
     apps_to_check = {}
     if args.app is None:
@@ -84,7 +90,8 @@ def run(args, persoconf, logger):
 
                     _compare_and_log( original_file_path,
                                       persoconf_backup_path,
-                                      logger )
+                                      logger,
+                                      difftool )
 
                 # 2) If not, it must be a real filename
                 else:
@@ -101,7 +108,8 @@ def run(args, persoconf, logger):
 
                         _compare_and_log( original_file_path,
                                           persoconf_backup_path,
-                                          logger )
+                                          logger,
+                                          difftool )
 
 
                     # 3) Otherwise, no idea what it is
@@ -125,11 +133,15 @@ def run(args, persoconf, logger):
 
                 _compare_and_log( original_file_path,
                                   persoconf_backup_path,
-                                  logger )
+                                  logger,
+                                  difftool )
 
 
 # -----------------------------------------------------------------------------
-def _compare_and_log(original_file_path, persoconf_backup_path, logger):
+def _compare_and_log( original_file_path,
+                      persoconf_backup_path,
+                      logger,
+                      difftool = None ):
     """Compare a file with its persoconf backup and log the result (at info
        level if the files are matching, warning level if they are not)."""
     
@@ -158,6 +170,8 @@ def _compare_and_log(original_file_path, persoconf_backup_path, logger):
             else:
                 logger.warning( "File %s was modified"
                                 % original_file_path )
+                if difftool:
+                    subprocess.call([ difftool, resolved_pbp, resolved_ofp ])
 
         except FileNotFoundError as err:
             if err.filename == resolved_pbp: