diff --git a/matlab/global_initialization.m b/matlab/global_initialization.m
index fc2282eddf427604a161e0edf902dcb2dedbf1b4..14fb4c590c1c21d9476efb3f4206675e6fc1d7a1 100644
--- a/matlab/global_initialization.m
+++ b/matlab/global_initialization.m
@@ -282,3 +282,6 @@ options_.ms.print_draws = 1;
 options_.ms.n_draws=1000;
 options_.ms.thinning_factor=1;
 options_.ms.proposal_draws = 100000;
+
+% initialize persistent variables in priordens()
+priordens([],[],[],[],[],[],1);