diff --git a/src/command_network.cc b/src/command_network.cc
index bf662cb4..11fa808d 100644
--- a/src/command_network.cc
+++ b/src/command_network.cc
@@ -244,7 +244,7 @@ cg_get_index(const torrent::Object& raw_args) {
   size_t index = 0;
 
   if (arg.is_string()) {
-    if (!rpc::parse_whole_value_nothrow(arg.as_string().c_str(), &index))
+    if (!rpc::parse_whole_value_nothrow(arg.as_string().c_str(), (int64_t*)&index))
       return torrent::resource_manager()->group_index_of(arg.as_string());
 
   } else {