diff --git a/gguf-py/gguf/constants.py b/gguf-py/gguf/constants.py
index 82febc4b6..af7408be9 100644
--- a/gguf-py/gguf/constants.py
+++ b/gguf-py/gguf/constants.py
@@ -1236,6 +1236,7 @@ LlamaFileTypeMap: dict[LlamaFileType, GGMLQuantizationType] = {
     LlamaFileType.MOSTLY_Q4_0_8_8: GGMLQuantizationType.Q4_0_8_8,
 }
 
+
 class GGUFEndian(IntEnum):
     LITTLE = 0
     BIG = 1
diff --git a/gguf-py/gguf/quants.py b/gguf-py/gguf/quants.py
index 3f0e58db1..abc621163 100644
--- a/gguf-py/gguf/quants.py
+++ b/gguf-py/gguf/quants.py
@@ -69,12 +69,12 @@ class __Quant(ABC):
     @classmethod
     @abstractmethod
     def quantize_blocks(cls, blocks: np.ndarray) -> np.ndarray:
-        raise NotImplemented
+        raise NotImplementedError
 
     @classmethod
     @abstractmethod
     def dequantize_blocks(cls, blocks: np.ndarray) -> np.ndarray:
-        raise NotImplemented
+        raise NotImplementedError
 
     @classmethod
     def quantize_rows(cls, rows: np.ndarray) -> np.ndarray: