diff --git a/gtda/homology/simplicial.py b/gtda/homology/simplicial.py
index 18702913..81cd2199 100644
--- a/gtda/homology/simplicial.py
+++ b/gtda/homology/simplicial.py
@@ -432,7 +432,7 @@ class WeightedRipsPersistence(BaseEstimator, TransformerMixin, PlotterMixin):
         is a parameter (see `weight_params`). If a callable, it must return
         non-negative 1D arrays.
 
-    weight_params : dict, optional, default: ``None``
+    weight_params : dict, optional, default: ``{}``
         Additional parameters for the weighted filtration. ``"p"`` determines
         the power to be used in computing edge weights from vertex weights. It
         can be one of ``1``, ``2`` or ``np.inf`` and defaults to ``1``. If
@@ -525,7 +525,7 @@ class WeightedRipsPersistence(BaseEstimator, TransformerMixin, PlotterMixin):
             "of": {"type": int, "in": Interval(0, np.inf, closed="left")}
             },
         "weights": {"type": (str, FunctionType)},
-        "weight_params": {"type": (dict, type(None))},
+        "weight_params": {"type": dict},
         "collapse_edges": {"type": bool},
         "coeff": {"type": int, "in": Interval(2, np.inf, closed="left")},
         "max_edge_weight": {"type": Real},
@@ -534,7 +534,7 @@ class WeightedRipsPersistence(BaseEstimator, TransformerMixin, PlotterMixin):
         }
 
     def __init__(self, metric="euclidean", metric_params={},
-                 homology_dimensions=(0, 1), weights="DTM", weight_params=None,
+                 homology_dimensions=(0, 1), weights="DTM", weight_params={},
                  collapse_edges=False, coeff=2, max_edge_weight=np.inf,
                  infinity_values=None, reduced_homology=True, n_jobs=None):
         self.metric = metric
@@ -616,7 +616,7 @@ def fit(self, X, y=None):
             self.effective_weight_params_.update({"n_neighbors": 3, "r": 2})
         else:
             key = "general"
-        if self.weight_params is not None:
+        if self.weight_params:
             self.effective_weight_params_.update(self.weight_params)
             validate_params(self.effective_weight_params_,
                             _AVAILABLE_RIPS_WEIGHTS[key])