diff --git a/matlab/priordens.m b/matlab/priordens.m
index 632b86d83c3a2d9a6386c3bb6ffd5e040d81d4be..b988e7ea1a4d123d7c453a7ad63610c2302ee2f0 100644
--- a/matlab/priordens.m
+++ b/matlab/priordens.m
@@ -144,7 +144,7 @@ if tt5
     if any(x(id5)-p3(id5)<0) || any(x(id5)-p4(id5)>0)
         logged_prior_density = -Inf ;
         if nargout ==4
-            info=id5(any(x(id5)-p3(id5)<0) || any(x(id5)-p4(id5)>0));
+            info=id5((x(id5)-p3(id5)<0) || (x(id5)-p4(id5)>0));
         end
         return
     end