diff --git a/skore/src/skore/_sklearn/_estimator/data_accessor.py b/skore/src/skore/_sklearn/_estimator/data_accessor.py
index 201f371902..80236007b3 100644
--- a/skore/src/skore/_sklearn/_estimator/data_accessor.py
+++ b/skore/src/skore/_sklearn/_estimator/data_accessor.py
@@ -50,6 +50,10 @@ def _retrieve_data_as_frame(
             raise ValueError(err_msg.format(f"X_{dataset}", data_source))
         elif not sbd.is_dataframe(X):
             X = pd.DataFrame(X, columns=[f"Feature {i}" for i in range(X.shape[1])])
+        else:
+            if not all(isinstance(col, str) for col in X.columns):
+                X = X.copy()
+                X.columns = [str(col) for col in X.columns]
 
         if with_y:
             if y is None:
@@ -63,6 +67,13 @@ def _retrieve_data_as_frame(
                 else:
                     columns = [f"Target {i}" for i in range(y.shape[1])]
                 y = pd.DataFrame(y, columns=columns)
+            else:
+                if not all(isinstance(col, str) for col in y.columns):
+                    y = y.copy()
+                    if y.shape[1] == 1 and list(y.columns) == [0]:
+                        y.columns = ["Target"]
+                    else:
+                        y.columns = [str(col) for col in y.columns]
 
         return X, y
 
diff --git a/skore/tests/unit/displays/table_report/test_estimator.py b/skore/tests/unit/displays/table_report/test_estimator.py
index 29b626908e..cfdb0b075a 100644
--- a/skore/tests/unit/displays/table_report/test_estimator.py
+++ b/skore/tests/unit/displays/table_report/test_estimator.py
@@ -69,6 +69,8 @@ def test_constructor(display):
         pd.DataFrame(
             np.ones((100, 5)), columns=[f"Feature number {i}" for i in range(5)]
         ),
+        pd.DataFrame(np.ones((100, 5))),
+        pd.DataFrame(np.ones((100, 5)), columns=["a", 1, "c", 3, "e"]),
     ],
 )
 @pytest.mark.parametrize(
@@ -78,6 +80,7 @@ def test_constructor(display):
         np.ones(100),
         pd.Series(np.ones(100)),
         pd.DataFrame(np.ones((100, 1)), columns=["Target"]),
+        pd.DataFrame(np.ones((100, 1))),
     ],
 )
 def test_X_y(X, y):