diff --git a/src/xml/openmc_fox.F90 b/src/xml/openmc_fox.F90
index fd4165efd4..461c6bc2b7 100644
--- a/src/xml/openmc_fox.F90
+++ b/src/xml/openmc_fox.F90
@@ -41,6 +41,8 @@ module openmc_fox
     logical :: doneChildren, doneAttributes, allElements
     integer :: i, i_tree
 
+    list => null()
+
     if (.not.associated(doc)) then
       if (getFoX_checks().or.FoX_NODE_IS_NULL<200) then
   call throw_exception(FoX_NODE_IS_NULL, "getElementsByTagName", ex)