diff --git a/mercurial/hook.py b/mercurial/hook.py
--- a/mercurial/hook.py
+++ b/mercurial/hook.py
@@ -138,6 +138,9 @@ def redirect(state):
     _redirect = state
 
 def hook(ui, repo, name, throw=False, **args):
+    if not ui.callhooks:
+        return False
+
     r = False
 
     oldstdout = -1
diff --git a/mercurial/ui.py b/mercurial/ui.py
--- a/mercurial/ui.py
+++ b/mercurial/ui.py
@@ -19,6 +19,7 @@ class ui(object):
         self._ucfg = config.config() # untrusted
         self._trustusers = set()
         self._trustgroups = set()
+        self.callhooks = True
 
         if src:
             self.fout = src.fout
@@ -31,6 +32,7 @@ class ui(object):
             self._trustusers = src._trustusers.copy()
             self._trustgroups = src._trustgroups.copy()
             self.environ = src.environ
+            self.callhooks = src.callhooks
             self.fixconfig()
         else:
             self.fout = sys.stdout