diff --git a/src/nasal_import.cpp b/src/nasal_import.cpp
index a3c6228..8fd893e 100644
--- a/src/nasal_import.cpp
+++ b/src/nasal_import.cpp
@@ -330,11 +330,11 @@ return_expr* linker::generate_module_return(code_block* block) {
     auto value = new hash_expr(block->get_location());
     result->set_value(value);
     for (const auto& i : finder->do_find(block)) {
-        auto pair = new hash_pair(block->get_location());
         // do not export symbol begins with '_'
         if (i.name.length() && i.name[0]=='_') {
             continue;
         }
+        auto pair = new hash_pair(block->get_location());
         pair->set_name(i.name);
         pair->set_value(new identifier(block->get_location(), i.name));
         value->add_member(pair);