diff --git a/ovsdbapp/venv.py b/ovsdbapp/venv.py
index 51cff106..a0e8b4d2 100644
--- a/ovsdbapp/venv.py
+++ b/ovsdbapp/venv.py
@@ -134,7 +134,7 @@ class OvsOvnVenvFixture(OvsVenvFixture):
 
     def __init__(self, *args, **kwargs):
         self.add_chassis = kwargs.pop('add_chassis', False)
-        self.ovndir = kwargs.pop('ovndir') or const.OVN_INSTALL_SHARE_PATH
+        self.ovndir = kwargs.pop('ovndir', const.OVN_INSTALL_SHARE_PATH)
         self.PATH_VAR_TEMPLATE += (
             ":{0}/controller:{0}/northd:{0}/utilities".format(
                 self.ovndir))
diff --git a/tools/debug_venv b/tools/debug_venv
index 6cb97851..93b66ccd 100755
--- a/tools/debug_venv
+++ b/tools/debug_venv
@@ -60,4 +60,4 @@ if [ -n "$regex" -a -z "$ovsvenv" ]; then
     ovsvenv=$(head -1 $test_file)
 fi
 echo "Debugging OVS virtual environment: $ovsvenv$test_match"
-tools/debug_venv.py $ovsvenv $VIRTUAL_ENV/src/ovs
+tools/debug_venv.py $ovsvenv $VIRTUAL_ENV/src/ovs $VIRTUAL_ENV/src/ovn
diff --git a/tools/debug_venv.py b/tools/debug_venv.py
index ea82afa1..78d09003 100755
--- a/tools/debug_venv.py
+++ b/tools/debug_venv.py
@@ -22,8 +22,8 @@ from fixtures import fixture
 
 from ovsdbapp import venv
 
-if len(sys.argv) != 3:
-    print("Requires two arguments: venvdir ovsdir", file=sys.stderr)
+if len(sys.argv) != 4:
+    print("Requires three arguments: venvdir ovsdir ovndir", file=sys.stderr)
     sys.exit(1)
 
 for d in sys.argv[1:]:
@@ -33,8 +33,9 @@ for d in sys.argv[1:]:
 
 venvdir = os.path.abspath(sys.argv[1])
 ovsdir = os.path.abspath(sys.argv[2])
+ovndir = os.path.abspath(sys.argv[3])
 
-v = venv.OvsOvnVenvFixture(venvdir, ovsdir)
+v = venv.OvsOvnVenvFixture(venvdir, ovsdir, ovndir=ovndir)
 try:
     atexit.register(v.cleanUp)
     v.setUp()