diff --git a/notletters/methods.py b/notletters/methods.py
index 6166872..285e17e 100644
--- a/notletters/methods.py
+++ b/notletters/methods.py
@@ -33,6 +33,7 @@ class LettersMethod(
     http_method=HTTPMethod.POST,
     api_method="/letters",
     returning=LettersResponse,
+    response_data_key=["letters"],
 ):
     email: str
     password: str = Field(repr=False)