diff --git a/bilby/core/result.py b/bilby/core/result.py
index 349f4f801960cfaf3a3f370c9d168211f16b9e8d..873ac2e31b5e0e5bfbfa841d2dab517c741baebd 100644
--- a/bilby/core/result.py
+++ b/bilby/core/result.py
@@ -1284,7 +1284,7 @@ class ResultList(list):
     def _check_consistent_priors(self):
         for res in self:
             for p in self[0].search_parameter_keys:
-                if not self[0].priors[p] == res.priors[p] or len(self[0].priors) != res.priors:
+                if not self[0].priors[p] == res.priors[p] or len(self[0].priors) != len(res.priors):
                     raise CombineResultError("Cannot combine results: inconsistent priors")
 
     def _check_consistent_parameters(self):