diff --git a/hgext/phabricator.py b/hgext/phabricator.py
--- a/hgext/phabricator.py
+++ b/hgext/phabricator.py
@@ -238,8 +238,9 @@
 
     def decorate(fn):
         def inner(*args, **kwargs):
-            if kwargs.get('test_vcr'):
-                cassette = pycompat.fsdecode(kwargs.pop('test_vcr'))
+            vcr = kwargs.pop('test_vcr')
+            if vcr:
+                cassette = pycompat.fsdecode(vcr)
                 import hgdemandimport
 
                 with hgdemandimport.deactivated():
diff --git a/tests/test-phabricator.t b/tests/test-phabricator.t
--- a/tests/test-phabricator.t
+++ b/tests/test-phabricator.t
@@ -24,16 +24,9 @@
   > EOF
   $ VCR="$TESTDIR/phabricator"
 
-BROKEN: debugcallconduit fails without --test-vcr:
+debugcallconduit doesn't claim invalid arguments without --test-vcr:
   $ echo '{}' | HGRCSKIPREPO= hg debugcallconduit 'conduit.ping'
-  hg debugcallconduit: invalid arguments
-  hg debugcallconduit METHOD
-  
-  call Conduit API
-  
-  options:
-  
-  (use 'hg debugcallconduit -h' to show more help)
+  abort: config phabricator.url is required
   [255]
 
 Error is handled reasonably. We override the phabtoken here so that