diff --git a/cfbs/__main__.py b/cfbs/__main__.py
index e359cf86..9a17f8a7 100755
--- a/cfbs/__main__.py
+++ b/cfbs/__main__.py
@@ -9,4 +9,5 @@
 
     from cfbs.main import main
 
-    main()
+    rc = main()
+    sys.exit(rc)
diff --git a/cfbs/commands.py b/cfbs/commands.py
index cfb92e94..c8b86cf9 100644
--- a/cfbs/commands.py
+++ b/cfbs/commands.py
@@ -21,7 +21,7 @@
     sh,
 )
 
-from cfbs.pretty import pretty_file, pretty
+from cfbs.pretty import pretty_check_file, pretty_file, pretty
 from cfbs.index import Index
 
 
@@ -42,18 +42,28 @@ def put_definition(data: dict):
         f.write(pretty(data))
 
 
-def pretty_command(filenames: list) -> int:
+def pretty_command(filenames: list, check) -> int:
     if not filenames:
         user_error("Filenames missing for cfbs pretty command")
+
+    num_files = 0
     for f in filenames:
         if not f or not f.endswith(".json"):
             user_error(
                 f"cfbs pretty command can only be used with .json files, not '{os.path.basename(f)}'"
             )
         try:
-            pretty_file(f)
+            if check:
+                if not pretty_check_file(f):
+                    num_files += 1
+                    print("Would reformat %s" % f)
+            else:
+                pretty_file(f)
         except FileNotFoundError:
             user_error(f"File '{f}' not found")
+    if check:
+        print("Would reformat %d file(s)" % num_files)
+        return 1 if num_files > 0 else 0
     return 0
 
 
diff --git a/cfbs/main.py b/cfbs/main.py
index 774be93d..65038da4 100644
--- a/cfbs/main.py
+++ b/cfbs/main.py
@@ -36,6 +36,9 @@ def get_args():
         "--force", help="Force rebuild / redownload", action="store_true"
     )
     parser.add_argument("--index", help="Specify alternate index", type=str)
+    parser.add_argument(
+        "--check", help="Check if file(s) would be reformatted", action="store_true"
+    )
 
     args = parser.parse_args()
     return args
@@ -74,7 +77,7 @@ def main() -> int:
     if args.command == "search":
         return commands.search_command(args.args, index=args.index)
     if args.command == "pretty":
-        return commands.pretty_command(args.args)
+        return commands.pretty_command(args.args, args.check)
 
     if not is_cfbs_repo():
         user_error("This is not a cfbs repo, to get started, type: cfbs init")
diff --git a/cfbs/pretty.py b/cfbs/pretty.py
index 8d418303..7dbea4df 100644
--- a/cfbs/pretty.py
+++ b/cfbs/pretty.py
@@ -2,6 +2,18 @@
 from collections import OrderedDict
 
 
+def pretty_check_file(filename):
+    with open(filename) as f:
+        s = f.read()
+    o = json.loads(s, object_pairs_hook=OrderedDict)
+    return s == pretty(o) + "\n"
+
+
+def pretty_check_string(s):
+    o = json.loads(s, object_pairs_hook=OrderedDict)
+    return s == pretty(o)
+
+
 def pretty_file(filename):
     with open(filename) as f:
         data = f.read()
diff --git a/test/test_pretty.py b/test/test_pretty.py
index 361dd28f..0cacaf7f 100644
--- a/test/test_pretty.py
+++ b/test/test_pretty.py
@@ -1,5 +1,5 @@
 from collections import OrderedDict
-from cfbs.pretty import pretty, pretty_string
+from cfbs.pretty import pretty, pretty_check_string, pretty_string
 
 
 def test_pretty():
@@ -181,3 +181,18 @@ def test_pretty_string():
   }
 ]"""
     assert pretty_string(test) == expected
+
+
+def test_pretty_check_string():
+    assert pretty_check_string(' "Hello" ') == False
+    assert pretty_check_string('"Hello"') == True
+    assert (
+        pretty_check_string(
+            """{
+  "name": "lars",
+  "age": 27
+}"""
+        )
+        == False
+    )
+    assert pretty_check_string('{ "name": "lars", "age": 27 }') == True