diff --git a/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/porter.yaml b/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/porter.yaml
index 75540ef8e..c6b001607 100644
--- a/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/porter.yaml
+++ b/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/porter.yaml
@@ -1,7 +1,7 @@
 ---
 schemaVersion: 1.0.0
 name: tre-service-guacamole-linuxvm
-version: 1.2.6
+version: 1.2.7
 description: "An Azure TRE User Resource Template for Guacamole (Linux)"
 dockerfile: Dockerfile.tmpl
 registry: azuretre
diff --git a/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/terraform/locals.tf b/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/terraform/locals.tf
index 438dc9c8e..f178c0410 100644
--- a/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/terraform/locals.tf
+++ b/templates/workspace_services/guacamole/user_resources/guacamole-azure-linuxvm/terraform/locals.tf
@@ -8,10 +8,10 @@ locals {
   keyvault_name                  = lower("kv-${substr(local.workspace_resource_name_suffix, -20, -1)}")
   storage_name                   = lower(replace("stg${substr(local.workspace_resource_name_suffix, -8, -1)}", "-", ""))
   admin_username = (
-    length(data.azuread_user.user.mail) > 0 && contains(data.azuread_user.user.user_principal_name, "#EXT#") ?
+    length(data.azuread_user.user.mail) > 0 && strcontains(data.azuread_user.user.user_principal_name, "#EXT#") ?
     substr(element(split("@", data.azuread_user.user.mail), 0), 0, 20) :
     substr(
-      contains(element(split("@", data.azuread_user.user.user_principal_name), 0), "#EXT#") ?
+      strcontains(element(split("@", data.azuread_user.user.user_principal_name), 0), "#EXT#") ?
       element(split("#EXT#", element(split("@", data.azuread_user.user.user_principal_name), 0)), 0) :
       element(split("@", data.azuread_user.user.user_principal_name), 0),
       0, 20
diff --git a/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/porter.yaml b/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/porter.yaml
index 93a616c63..c9b6f2183 100644
--- a/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/porter.yaml
+++ b/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/porter.yaml
@@ -1,7 +1,7 @@
 ---
 schemaVersion: 1.0.0
 name: tre-service-guacamole-windowsvm
-version: 1.2.8
+version: 1.2.9
 description: "An Azure TRE User Resource Template for Guacamole (Windows 10)"
 dockerfile: Dockerfile.tmpl
 registry: azuretre
diff --git a/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/terraform/locals.tf b/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/terraform/locals.tf
index d8b120108..e9316dbeb 100644
--- a/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/terraform/locals.tf
+++ b/templates/workspace_services/guacamole/user_resources/guacamole-azure-windowsvm/terraform/locals.tf
@@ -8,10 +8,10 @@ locals {
   keyvault_name                  = lower("kv-${substr(local.workspace_resource_name_suffix, -20, -1)}")
   storage_name                   = lower(replace("stg${substr(local.workspace_resource_name_suffix, -8, -1)}", "-", ""))
   admin_username = (
-    length(data.azuread_user.user.mail) > 0 && contains(data.azuread_user.user.user_principal_name, "#EXT#") ?
+    length(data.azuread_user.user.mail) > 0 && strcontains(data.azuread_user.user.user_principal_name, "#EXT#") ?
     substr(element(split("@", data.azuread_user.user.mail), 0), 0, 20) :
     substr(
-      contains(element(split("@", data.azuread_user.user.user_principal_name), 0), "#EXT#") ?
+      strcontains(element(split("@", data.azuread_user.user.user_principal_name), 0), "#EXT#") ?
       element(split("#EXT#", element(split("@", data.azuread_user.user.user_principal_name), 0)), 0) :
       element(split("@", data.azuread_user.user.user_principal_name), 0),
       0, 20