diff --git a/backend/app/core/config.py b/backend/app/core/config.py
index f2437df..b7b4583 100644
--- a/backend/app/core/config.py
+++ b/backend/app/core/config.py
@@ -16,7 +16,7 @@ class Settings(BaseSettings):
         validation_alias=AliasChoices("DATABASE_URL", "LETTERFEED_DATABASE_URL"),
     )
     app_base_url: str = Field(
-        "http://localhost:8000",
+        "http://backend:8000",
         validation_alias=AliasChoices("APP_BASE_URL", "LETTERFEED_APP_BASE_URL"),
     )
     imap_server: str = ""