diff --git a/src/containerapp/azext_containerapp/_up_utils.py b/src/containerapp/azext_containerapp/_up_utils.py
index cdd1b0814d7..aded983adee 100644
--- a/src/containerapp/azext_containerapp/_up_utils.py
+++ b/src/containerapp/azext_containerapp/_up_utils.py
@@ -792,7 +792,7 @@ def validate_environment_location(cmd, location):
     
     location_count = {}
     for loc in locations:
-        location_count[loc] = sum(1 for e in env_list if e["location"] == loc)
+        location_count[loc] = len([e for e in env_list if e["location"] == loc])
 
     disallowed_locations = []
     for _, value in enumerate(location_count):
@@ -802,10 +802,7 @@ def validate_environment_location(cmd, location):
     res_locations = list_environment_locations(cmd)
     res_locations = [l for l in res_locations if l not in disallowed_locations]
 
-    allowed_locs = ""
-    for res_loc in res_locations:
-        allowed_locs += res_loc + ", "
-    allowed_locs = allowed_locs[:-2]
+    allowed_locs = ", ".join(res_locations)
 
     if location:
         try:
@@ -839,6 +836,8 @@ def list_environment_locations(cmd):
 
 
 def check_env_name_on_rg(cmd, managed_env, resource_group_name, location):
+    if location:
+        _ensure_location_allowed(cmd, location, "Microsoft.App", "managedEnvironments")
     if managed_env and resource_group_name and location:
         env_def = None
         try:
@@ -847,4 +846,4 @@ def check_env_name_on_rg(cmd, managed_env, resource_group_name, location):
             pass
         if env_def:
             if location != env_def["location"]:
-                raise ValidationError("Environment {} already exists in resource group {} on location {}, cannot change location of existing environment to {}.".format(parse_resource_id(managed_env)["name"], resource_group_name, env_def["location"]), location)
\ No newline at end of file
+                raise ValidationError("Environment {} already exists in resource group {} on location {}, cannot change location of existing environment to {}.".format(parse_resource_id(managed_env)["name"], resource_group_name, env_def["location"], location))
\ No newline at end of file
diff --git a/src/containerapp/azext_containerapp/custom.py b/src/containerapp/azext_containerapp/custom.py
index 638bbcff163..fe7b0ecbf04 100644
--- a/src/containerapp/azext_containerapp/custom.py
+++ b/src/containerapp/azext_containerapp/custom.py
@@ -2015,12 +2015,14 @@ def containerapp_up(cmd,
                     service_principal_tenant_id=None):
     from ._up_utils import (_validate_up_args, _reformat_image, _get_dockerfile_content, _get_ingress_and_target_port,
                             ResourceGroup, ContainerAppEnvironment, ContainerApp, _get_registry_from_app,
-                            _get_registry_details, _create_github_action, _set_up_defaults, up_output, AzureContainerRegistry)
+                            _get_registry_details, _create_github_action, _set_up_defaults, up_output, AzureContainerRegistry,
+                            check_env_name_on_rg)
     HELLOWORLD = "mcr.microsoft.com/azuredocs/containerapps-helloworld"
     dockerfile = "Dockerfile"  # for now the dockerfile name must be "Dockerfile" (until GH actions API is updated)
 
     _validate_up_args(source, image, repo)
     validate_container_app_name(name)
+    check_env_name_on_rg(cmd, managed_env, resource_group_name, location)
 
     image = _reformat_image(source, repo, image)
     token = None if not repo else get_github_access_token(cmd, ["admin:repo_hook", "repo", "workflow"], token)