diff --git a/kcc/cli.py b/kcc/cli.py
index 58d0355..3a8a6fa 100644
--- a/kcc/cli.py
+++ b/kcc/cli.py
@@ -15,7 +15,8 @@
 
 def run(*,
         config_file: str = '',
-        query: bool = False):
+        query: bool = False,
+        missings: bool = False):
     if query:
         must_be_set, must_be_set_or_module, must_be_unset = \
                 KernelSelfProtectionProject()
@@ -24,11 +25,14 @@ def run(*,
         must_be_unset.update(MUST_BE_UNSET)
 
     kconfig = Kconfig.default()
-    results = kconfig.check(config_file)
-    if not results:
+    results, missing_keys = kconfig.check(config_file)
+    if not results and not missing_keys:
         return
     for opt, msg in results.items():
         print(opt, msg)
+    if missings:
+        for key in missing_keys:
+            print(key)
     return 1
 
 def cli() -> None:
@@ -36,6 +40,7 @@ def cli() -> None:
     parser.add_argument('config_file', nargs='?', type=argparse.FileType('r'),
             default=sys.stdin)
     parser.add_argument('--query', default=False, action='store_true')
+    parser.add_argument('--missings', default=False, action='store_true')
     args = parser.parse_args()
     ret = run(**vars(args))
     args.config_file.close()
diff --git a/kcc/kconfig.py b/kcc/kconfig.py
index 76faf98..b743b31 100644
--- a/kcc/kconfig.py
+++ b/kcc/kconfig.py
@@ -23,6 +23,7 @@ class Kconfig(object):
     Y_MUST_N = "is set but is required to be not set (%s)"
     M_MUST_Y = "is set as =m but is required to be set to y (%s)"
     M_MUST_N = "is set as =m but is required to be not set (%s)"
+    MISSING_MUST_BE_SET  = "\nIs not in config file and must be set:"
 
     def __init__(self, *,
             must_be_set: Dict[str, str] = {},
@@ -40,12 +41,26 @@ def default(cls):
 
     def check(self, stream: Iterable[str]) -> Dict[str, str]:
         results: Dict[str, str] = {}
+        missing = []
+        missing_key_mbs = list(self.must_be_set.keys())
+        missing_key_mbsom = list(self.must_be_set_or_module.keys())
+
         for line in stream:
+            line = line.strip()
             results.update(self.check_line(line))
-        return results
+            line = line.lstrip("#").rstrip("=y").lstrip(" ").rstrip(" is not set").rstrip(" ")
+            for mbs_key in missing_key_mbs:
+                if mbs_key == line:
+                    missing_key_mbs.remove(mbs_key)
+            for mbsom_key in missing_key_mbsom:
+                if mbsom_key == line:
+                    missing_key_mbsom.remove(mbsom_key)
+
+        missing =  missing_key_mbs + missing_key_mbsom
+        missing.insert(0,self.MISSING_MUST_BE_SET)
+        return results, missing
 
     def check_line(self, line: str) -> Dict[str, str]:
-        line = line.strip()
         match = re.search("^# (CONFIG_.*) is not set", line)
         if match:
             notset = match.group(1)