diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 0b1d5ce65c18f4ab5b736b2ec2972b38acb9afe3..7ac4d4eeae976472ee31b54bfbc856ac6b94cfe5 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -15798,7 +15798,7 @@ class LUNetworkAdd(LogicalUnit):
     try:
       pool = network.AddressPool.InitializeNetwork(nobj)
     except errors.AddressPoolError, e:
-      raise errors.OpExecError("Cannot create IP pool for this network. %s" % e)
+      raise errors.OpExecError("Cannot create IP pool for this network: %s" % e)
 
     # Check if we need to reserve the nodes and the cluster master IP
     # These may not be allocated to any instances in routed mode, as