diff --git a/pygitguardian/client.py b/pygitguardian/client.py
index 61d96266..db8f2f2f 100644
--- a/pygitguardian/client.py
+++ b/pygitguardian/client.py
@@ -584,9 +584,10 @@ def read_metadata(self) -> Optional[Detail]:
             result.status_code = resp.status_code
             return result
         metadata = ServerMetadata.from_dict(resp.json())
-        metadata.secret_scan_preferences.general__maximum_payload_size = (
-            metadata.preferences["general__maximum_payload_size"]
-        )
+        if "general__maximum_payload_size" in metadata.preferences:
+            metadata.secret_scan_preferences.general__maximum_payload_size = (
+                metadata.preferences["general__maximum_payload_size"]
+            )
         self.secret_scan_preferences = metadata.secret_scan_preferences
         return None
 
diff --git a/pygitguardian/config.py b/pygitguardian/config.py
index adb1790c..462d4656 100644
--- a/pygitguardian/config.py
+++ b/pygitguardian/config.py
@@ -4,4 +4,4 @@
 
 MULTI_DOCUMENT_LIMIT = 20
 DOCUMENT_SIZE_THRESHOLD_BYTES = 1048576  # 1MB
-GENERAL_MAXIMUM_PAYLOAD = 2621440  # 2.5MB
+GENERAL_MAXIMUM_PAYLOAD = 2621440  # 25MB