diff --git a/environments/net-bond-with-vlans.yaml b/environments/net-bond-with-vlans.yaml
index 73f71324cb..9600fc7e2e 100644
--- a/environments/net-bond-with-vlans.yaml
+++ b/environments/net-bond-with-vlans.yaml
@@ -12,7 +12,11 @@ resource_registry:
   OS::TripleO::ObjectStorage::Net::SoftwareConfig: ../network/config/bond-with-vlans/swift-storage.yaml
   OS::TripleO::CephStorage::Net::SoftwareConfig: ../network/config/bond-with-vlans/ceph-storage.yaml
 
-parameters:
+# We use parameter_defaults instead of parameters here because Tuskar munges
+# the names of top level and role level parameters with the role name and a
+# version. Using parameter_defaults makes it such that if the parameter name is
+# not defined in the template, we don't get an error.
+parameter_defaults:
   # This sets 'external_network_bridge' in l3_agent.ini to an empty string
   # so that external networks act like provider bridge networks (they
   # will plug into br-int instead of br-ex)
diff --git a/environments/net-single-nic-with-vlans.yaml b/environments/net-single-nic-with-vlans.yaml
index 8561acd39a..bdfeadd3f3 100644
--- a/environments/net-single-nic-with-vlans.yaml
+++ b/environments/net-single-nic-with-vlans.yaml
@@ -12,7 +12,11 @@ resource_registry:
   OS::TripleO::ObjectStorage::Net::SoftwareConfig: ../network/config/single-nic-vlans/swift-storage.yaml
   OS::TripleO::CephStorage::Net::SoftwareConfig: ../network/config/single-nic-vlans/ceph-storage.yaml
 
-parameters:
+# We use parameter_defaults instead of parameters here because Tuskar munges
+# the names of top level and role level parameters with the role name and a
+# version. Using parameter_defaults makes it such that if the parameter name is
+# not defined in the template, we don't get an error.
+parameter_defaults:
   # This sets 'external_network_bridge' in l3_agent.ini to an empty string
   # so that external networks act like provider bridge networks (they
   # will plug into br-int instead of br-ex)