diff --git a/src/sktime_mcp/runtime/executor.py b/src/sktime_mcp/runtime/executor.py
index 0dc2673f..a1935e80 100644
--- a/src/sktime_mcp/runtime/executor.py
+++ b/src/sktime_mcp/runtime/executor.py
@@ -131,12 +131,16 @@ def fit(
             return {"success": False, "error": f"Handle not found: {handle_id}"}
 
         try:
-            if fh is not None:
-                instance.fit(y, X=X, fh=fh)
-            elif X is not None:
-                instance.fit(y, X=X)
+            is_classifier = getattr(instance, "_estimator_type", None) == "classifier"
+            if is_classifier:
+                instance.fit(X, y)
             else:
-                instance.fit(y)
+                if fh is not None:
+                    instance.fit(y, X=X, fh=fh)
+                elif X is not None:
+                    instance.fit(y, X=X)
+                else:
+                    instance.fit(y)
 
             self._handle_manager.mark_fitted(handle_id)
             return {"success": True, "handle": handle_id, "fitted": True}
@@ -159,10 +163,14 @@ def predict(
             return {"success": False, "error": "Estimator not fitted"}
 
         try:
-            if fh is None:
-                fh = list(range(1, 13))
+            is_classifier = getattr(instance, "_estimator_type", None) == "classifier"
+            if is_classifier:
+                predictions = instance.predict(X)
+            else:
+                if fh is None:
+                    fh = list(range(1, 13))
 
-            predictions = instance.predict(fh=fh, X=X) if X is not None else instance.predict(fh=fh)
+                predictions = instance.predict(fh=fh, X=X) if X is not None else instance.predict(fh=fh)
 
             if isinstance(predictions, pd.Series):
                 # Convert index to string to avoid JSON serialization issues with Period/DatetimeIndex