diff --git a/horizon/files/horizon_settings/_horizon_settings.py b/horizon/files/horizon_settings/_horizon_settings.py
index 3c9a6f1..02bd9a5 100644
--- a/horizon/files/horizon_settings/_horizon_settings.py
+++ b/horizon/files/horizon_settings/_horizon_settings.py
@@ -30,7 +30,7 @@
 {%- if app.launch_instance_defaults is defined %}
 LAUNCH_INSTANCE_DEFAULTS = {
     {%- for default_name, defaults in launch_data.items() %}
-    '{{ default_name }}': {{ defaults }},
+    "{{ default_name }}": {{ defaults }},
     {%- endfor %}
 }
 {%- endif %}