diff --git a/doubleml/rdd/rdd.py b/doubleml/rdd/rdd.py
index 858ae5ed..8db9171f 100644
--- a/doubleml/rdd/rdd.py
+++ b/doubleml/rdd/rdd.py
@@ -143,7 +143,10 @@ def __init__(
 
         self._check_effect_sign()
 
-        # TODO: Add further input checks
+        if ("h", "b") & kwargs.keys():
+            warnings.warn(f"Key-worded arguments contain: {('h', 'b') & kwargs.keys()}. \n \
+                            Iterative bandwidth selection will be overwritten by provided values.")
+
         self.kwargs = kwargs
 
         self._smpls = DoubleMLResampling(
@@ -453,10 +456,12 @@ def _update_weights(self):
     def _fit_rdd(self, h=None, b=None):
         if self.fuzzy:
             rdd_res = rdrobust.rdrobust(
-                y=self._M_Y[:, self._i_rep], x=self._score, fuzzy=self._M_D[:, self._i_rep], h=h, b=b, **self.kwargs
+                y=self._M_Y[:, self._i_rep], x=self._score, fuzzy=self._M_D[:, self._i_rep],
+                c=0, **({"h": h, "b": b} | self.kwargs)
             )
         else:
-            rdd_res = rdrobust.rdrobust(y=self._M_Y[:, self._i_rep], x=self._score, h=h, b=b, **self.kwargs)
+            rdd_res = rdrobust.rdrobust(y=self._M_Y[:, self._i_rep], x=self._score, fuzzy=None,
+                                        c=0, **({"h": h, "b": b} | self.kwargs))
         return rdd_res
 
     def _set_coefs(self, rdd_res, h):