diff --git a/cfg.sample.toml b/cfg.sample.toml
index 668aba9e..cef89016 100644
--- a/cfg.sample.toml
+++ b/cfg.sample.toml
@@ -10,6 +10,9 @@ access_token = ""
 app_client_id = ""
 app_client_secret = ""
 
+# Priority values above max_priority will be refused.
+max_priority = 9001
+
 [git]
 
 # Use the local Git command. Required to use some advanced features. It also
diff --git a/homu/main.py b/homu/main.py
index 556fa2e8..fb8727c4 100644
--- a/homu/main.py
+++ b/homu/main.py
@@ -517,10 +517,18 @@ def parse_commands(body, username, repo_cfg, state, my_username, db, states,
                                realtime, my_username):
                 continue
             try:
-                state.priority = int(word[len('p='):])
+                pvalue = int(word[len('p='):])
             except ValueError:
-                pass
+                continue
 
+            if pvalue > global_cfg['max_priority']:
+                if realtime:
+                    state.add_comment(
+                        ':stop_sign: Priority higher than @{} is ignored.'
+                        .format(global_cfg['max_priority'])
+                    )
+                continue
+            state.priority = pvalue
             state.save()
 
         elif word.startswith('delegate='):
diff --git a/setup.py b/setup.py
index 82b8844b..1c3fbaba 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@
 
 setup(
     name='homu',
-    version='0.2.0',
+    version='0.3.0',
     author='Barosl Lee',
     url='https://github.com/barosl/homu',
     description=('A bot that integrates with GitHub '