diff --git a/sdmetrics/reports/base_report.py b/sdmetrics/reports/base_report.py
index 1f67d009..3536b3e0 100644
--- a/sdmetrics/reports/base_report.py
+++ b/sdmetrics/reports/base_report.py
@@ -55,9 +55,6 @@ def validate(self, real_data, synthetic_data, metadata):
             metadata (dict):
                 The metadata of the table.
         """
-        if not isinstance(metadata, dict):
-            metadata = metadata.to_dict()
-
         self._validate_metadata_matches_data(real_data, synthetic_data, metadata)
 
     def _handle_results(self, verbose):
@@ -101,6 +98,9 @@ def generate(self, real_data, synthetic_data, metadata, verbose=True):
             verbose (bool):
                 Whether or not to print report summary and progress.
         """
+        if not isinstance(metadata, dict):
+            raise TypeError('The provided metadata is not a dictionary.')
+
         self.validate(real_data, synthetic_data, metadata)
         self.convert_datetimes(real_data, synthetic_data, metadata)
 
diff --git a/tests/unit/reports/test_base_report.py b/tests/unit/reports/test_base_report.py
index 90275f07..156b096a 100644
--- a/tests/unit/reports/test_base_report.py
+++ b/tests/unit/reports/test_base_report.py
@@ -152,6 +152,27 @@ def test_convert_datetimes(self):
         pd.testing.assert_frame_equal(real_data, expected_real_data)
         pd.testing.assert_frame_equal(synthetic_data, expected_synthetic_data)
 
+    def test_generate_metadata_not_dict(self):
+        """Test the ``generate`` method with metadata not being a dict."""
+        # Setup
+        base_report = BaseReport()
+        real_data = pd.DataFrame({
+            'column1': [1, 2, 3],
+            'column2': ['a', 'b', 'c']
+        })
+        synthetic_data = pd.DataFrame({
+            'column1': [1, 2, 3],
+            'column2': ['a', 'b', 'c']
+        })
+        metadata = 'metadata'
+
+        # Run and Assert
+        expected_message = (
+            'The provided metadata is not a dictionary.'
+        )
+        with pytest.raises(TypeError, match=expected_message):
+            base_report.generate(real_data, synthetic_data, metadata, verbose=False)
+
     def test_generate(self):
         """Test the ``generate`` method.