diff --git a/tupak/gw/likelihood.py b/tupak/gw/likelihood.py
index 0c9ed0043820f33185edf3af0c563294d9c450b3..b4d2bf13af516f51d9ee65967eb03e2bab43a752 100644
--- a/tupak/gw/likelihood.py
+++ b/tupak/gw/likelihood.py
@@ -64,6 +64,7 @@ class GravitationalWaveTransient(likelihood.Likelihood):
         self.prior = prior
 
         if self.distance_marginalization:
+            self.check_prior_is_set()
             self.distance_array = np.array([])
             self.delta_distance = 0
             self.distance_prior_array = np.array([])
@@ -71,10 +72,18 @@ class GravitationalWaveTransient(likelihood.Likelihood):
             prior['luminosity_distance'] = 1  # this means the prior is a delta function fixed at the RHS value
 
         if self.phase_marginalization:
+            self.check_prior_is_set()
             self.bessel_function_interped = None
             self.setup_phase_marginalization()
             prior['phase'] = 0
 
+        if self.time_marginalization:
+            self.check_prior_is_set()
+
+    def check_prior_is_set(self):
+        if self.prior is None:
+            raise ValueError("You can't use a marginalized likelihood without specifying a prior")
+
     @property
     def prior(self):
         return self.__prior