diff --git a/src/distribution.cpp b/src/distribution.cpp
index aa0e8e6843..32b47093cd 100644
--- a/src/distribution.cpp
+++ b/src/distribution.cpp
@@ -27,7 +27,7 @@ DiscreteIndex::DiscreteIndex(pugi::xml_node node)
   auto params = get_node_array<double>(node, "parameters");
   std::size_t n = params.size() / 2;
 
-  assign(&(*params.begin()), n);
+  assign(&(*params.begin()) + n, n);
 }
 
 DiscreteIndex::DiscreteIndex(const double* p, int n)