diff --git a/hc/api/apps.py b/hc/api/apps.py
index 2bac1c35..9644e809 100644
--- a/hc/api/apps.py
+++ b/hc/api/apps.py
@@ -14,7 +14,7 @@ class ApiConfig(AppConfig):
     name = "hc.api"
 
 
-@register()  # W001, W002, W005, E002
+@register()  # W001, W002, W005, E002, E003
 def settings_check(
     app_configs: Sequence[AppConfig] | None,
     databases: Sequence[str] | None,
@@ -61,6 +61,15 @@ def settings_check(
             )
         )
 
+    if settings.TIME_ZONE != "UTC":
+        items.append(
+            Error(
+                "settings.TIME_ZONE is not 'UTC'",
+                hint="Healthchecks is designed to use UTC internally, changing this setting will break things",
+                id="hc.api.E003",
+            )
+        )
+
     return items