diff --git a/quantum/common/exceptions.py b/quantum/common/exceptions.py
index cc91eeca57..9c041d66db 100644
--- a/quantum/common/exceptions.py
+++ b/quantum/common/exceptions.py
@@ -94,7 +94,7 @@ class InUse(QuantumException):
 
 class NetworkInUse(InUse):
     message = _("Unable to complete operation on network %(net_id)s. "
-                "There is one or more ports still in use on the network.")
+                "There are one or more ports still in use on the network.")
 
 
 class SubnetInUse(InUse):