diff --git a/pyext/src/restraints/parameters.py b/pyext/src/restraints/parameters.py
index c085d563..fed1d753 100644
--- a/pyext/src/restraints/parameters.py
+++ b/pyext/src/restraints/parameters.py
@@ -6,64 +6,30 @@
 import IMP.container
 import IMP.isd
 import IMP.pmi.tools
+import IMP.pmi.restraints
 
-class WeightRestraint(object):
 
-    def __init__(self, weight, lower, upper, kappa):
+class WeightRestraint(IMP.pmi.restraints.RestraintBase):
 
-        self.weight = weight
-        self.m = self.weight.get_model()
-        self.label = "None"
-        self.rs = IMP.RestraintSet(self.m, 'weight_restraint')
+    def __init__(self, w, lower, upper, kappa, label=None, weight=1.):
+        self.w = w
+        m = self.w.get_model()
+        super(WeightRestraint, self).__init__(m, label=label, weight=weight)
         self.lower = lower
         self.upper = upper
         self.kappa = kappa
         self.rs.add_restraint(
             IMP.isd.WeightRestraint(
-                self.weight,
+                self.w,
                 self.lower,
                 self.upper,
                 self.kappa))
 
-    def get_restraint(self, label):
-        return self.rs
 
-    def add_to_model(self):
-        IMP.pmi.tools.add_restraint_to_model(self.m, self.rs)
+class JeffreysPrior(IMP.pmi.restraints.RestraintBase):
 
-    def set_label(self, label):
-        self.label = label
-
-    def get_output(self):
-        self.m.update()
-        output = {}
-        score = self.rs.unprotected_evaluate(None)
-        output["_TotalScore"] = str(score)
-        output["WeightRestraint_" + self.label] = str(score)
-        return output
-
-
-class JeffreysPrior(object):
-
-    def __init__(self, nuisance):
-
-        self.m = nuisance.get_model()
-        self.label = "None"
-        self.rs = IMP.RestraintSet(self.m, 'jeffrey_prior')
+    def __init__(self, nuisance, label=None, weight=1.):
+        m = nuisance.get_model()
+        super(JeffreysPrior, self).__init__(m, label=label, weight=weight)
         jp = IMP.isd.JeffreysRestraint(self.m, nuisance)
         self.rs.add_restraint(jp)
-
-    def add_to_model(self):
-        IMP.pmi.tools.add_restraint_to_model(self.m, self.rs)
-
-    def set_label(self, label):
-        self.label = label
-
-    def get_output(self):
-        output = {}
-        score = self.rs.unprotected_evaluate(None)
-        output["_TotalScore"] = str(score)
-        output["JeffreyPrior_" + self.label] = str(score)
-        return output
-
-#