diff --git a/src/_zkapauthorizer/_plugin.py b/src/_zkapauthorizer/_plugin.py
index aeaa54b5cf694718965d7b4770e3f04bf7c1943e..a72586d8e69bb66c8eec1913c2a7c0e71aea90f7 100644
--- a/src/_zkapauthorizer/_plugin.py
+++ b/src/_zkapauthorizer/_plugin.py
@@ -307,4 +307,4 @@ def load_signing_key(path):
     :return challenge_bypass_ristretto.SigningKey: An object representing the
         key read.
     """
-    return SigningKey.decode_base64(path.getContent())
+    return SigningKey.decode_base64(path.getContent().strip())