diff --git a/src/Model/Types.hs b/src/Model/Types.hs
index 2f7d3318a..4e592e279 100644
--- a/src/Model/Types.hs
+++ b/src/Model/Types.hs
@@ -163,7 +163,7 @@ data SheetType
   | Bonus         { grading :: SheetGrading }
   | Informational { grading :: SheetGrading }
   | NotGraded
-  deriving (Eq, Read, Show)
+  deriving (Eq, Read, Show, Generic)
 
 deriveJSON defaultOptions
   { constructorTagModifier = camelToPathPiece