diff --git a/stack_orchestrator/deploy/webapp/deploy_webapp.py b/stack_orchestrator/deploy/webapp/deploy_webapp.py
index 54f833aa..5e77a8a4 100644
--- a/stack_orchestrator/deploy/webapp/deploy_webapp.py
+++ b/stack_orchestrator/deploy/webapp/deploy_webapp.py
@@ -15,6 +15,7 @@
 
 import click
 import os
+import yaml
 from pathlib import Path
 from urllib.parse import urlparse
 from tempfile import NamedTemporaryFile
@@ -36,26 +37,35 @@ def _fixup_container_tag(deployment_dir: str, image: str):
         wfile.write(contents)
 
 
-def _fixup_url_spec(spec_file_name: str, urls: list[str]):
+def fixup_url_spec(spec_file_name: str, urls: list[str]):
+    spec_file_path = Path(spec_file_name)
+
+    # Load existing spec
+    with open(spec_file_path, "r") as file:
+        spec_data = yaml.safe_load(file) or {}
+
+    # Build new http-proxy entries
     http_proxy_entries = []
     for url in urls:
         parsed_url = urlparse(url)
-        http_proxy_entries.append(f'''
-    - host-name: {parsed_url.hostname}
-      routes:
-        - path: '{parsed_url.path if parsed_url.path else "/"}'
-          proxy-to: webapp:80''')
+        http_proxy_entries.append({
+            "host-name": parsed_url.hostname,
+            "routes": [
+                {
+                    "path": parsed_url.path if parsed_url.path else "/",
+                    "proxy-to": "webapp:80"
+                }
+            ]
+        })
 
-    http_proxy_spec = f'''
-  http-proxy:{''.join(http_proxy_entries)}
-    '''
+    # Update the spec
+    if "network" not in spec_data:
+        spec_data["network"] = {}
+    spec_data["network"]["http-proxy"] = http_proxy_entries
 
-    spec_file_path = Path(spec_file_name)
-    with open(spec_file_path, "r") as rfile:
-        contents = rfile.read()
-    contents += http_proxy_spec
-    with open(spec_file_path, "w") as wfile:
-        wfile.write(contents)
+    # Write back the updated YAML
+    with open(spec_file_path, "w") as file:
+        yaml.dump(spec_data, file, default_flow_style=False, sort_keys=False)
 
 
 def create_deployment(ctx, deployment_dir, image, urls, kube_config, image_registry, env_file):
@@ -90,7 +100,7 @@ def create_deployment(ctx, deployment_dir, image, urls, kube_config, image_regis
         None
     )
     # Add the TLS and DNS spec
-    _fixup_url_spec(spec_file_name, urls)
+    fixup_url_spec(spec_file_name, urls)
     create_operation(
         deploy_command_context,
         spec_file_name,
diff --git a/stack_orchestrator/deploy/webapp/deploy_webapp_from_registry.py b/stack_orchestrator/deploy/webapp/deploy_webapp_from_registry.py
index 92c16bce..fa5500b2 100644
--- a/stack_orchestrator/deploy/webapp/deploy_webapp_from_registry.py
+++ b/stack_orchestrator/deploy/webapp/deploy_webapp_from_registry.py
@@ -26,6 +26,7 @@ import yaml
 import click
 import gnupg
 
+from stack_orchestrator import constants
 from stack_orchestrator.deploy.images import remote_image_exists
 from stack_orchestrator.deploy.webapp import deploy_webapp
 from stack_orchestrator.deploy.webapp.util import (
@@ -207,7 +208,8 @@ def process_app_deployment_request(
             deployment_config_file = os.path.join(deployment_dir, "config.env")
             shutil.copyfile(env_filename, deployment_config_file)
 
-        # TODO: Update spec with new urls
+        # Update existing deployment spec with new urls
+        deploy_webapp.fixup_url_spec(os.path.join(deployment_dir, constants.spec_file_name))
 
         # TODO: Update with deployment_container_tag if it's not a redeployment
         # as for redeployment, deployment_container_tag won't get built