diff --git a/feathr_project/feathr/definition/feature.py b/feathr_project/feathr/definition/feature.py
index 5ba577498..0720aced7 100644
--- a/feathr_project/feathr/definition/feature.py
+++ b/feathr_project/feathr/definition/feature.py
@@ -30,6 +30,11 @@ def __init__(self,
                  registry_tags: Optional[Dict[str, str]] = None,
                  ):
         FeatureBase.validate_feature_name(name)
+
+        # Validate the feature type
+        if not isinstance(feature_type, FeatureType):
+            raise KeyError(f'Feature type must be a FeatureType class, like INT32, but got {feature_type}')
+
         self.name = name
         self.feature_type = feature_type
         self.registry_tags=registry_tags
diff --git a/feathr_project/feathr/definition/typed_key.py b/feathr_project/feathr/definition/typed_key.py
index 16274698d..c2732a476 100644
--- a/feathr_project/feathr/definition/typed_key.py
+++ b/feathr_project/feathr/definition/typed_key.py
@@ -20,6 +20,10 @@ def __init__(self,
                  full_name: Optional[str] = None,
                  description: Optional[str] = None,
                  key_column_alias: Optional[str] = None) -> None:
+        # Validate the key_column type
+        if not isinstance(key_column_type, ValueType):
+            raise KeyError(f'key_column_type must be a ValueType, like Value.INT32, but got {key_column_type}')
+        
         self.key_column = key_column
         self.key_column_type = key_column_type
         self.full_name = full_name
diff --git a/feathr_project/test/unit/test_dtype.py b/feathr_project/test/unit/test_dtype.py
new file mode 100644
index 000000000..eb6aaf2ce
--- /dev/null
+++ b/feathr_project/test/unit/test_dtype.py
@@ -0,0 +1,24 @@
+import pytest
+from feathr import Feature, TypedKey, ValueType, INT32
+
+
+def test_key_type():
+    key = TypedKey(key_column="key", key_column_type=ValueType.INT32)
+    assert key.key_column_type == ValueType.INT32
+
+    with pytest.raises(KeyError):
+        key = TypedKey(key_column="key", key_column_type=INT32)
+
+def test_feature_type():
+    key = TypedKey(key_column="key", key_column_type=ValueType.INT32)
+
+    feature = Feature(name="name",
+                      key=key,
+                      feature_type=INT32)
+    
+    assert feature.feature_type == INT32
+
+    with pytest.raises(KeyError):
+        feature = Feature(name="name",
+                          key=key,
+                          feature_type=ValueType.INT32)
\ No newline at end of file