diff --git a/src/game_events.cpp b/src/game_events.cpp
index 8457c925123..264416fb489 100644
--- a/src/game_events.cpp
+++ b/src/game_events.cpp
@@ -986,7 +986,7 @@ bool event_handler::handle_event_command(const queued_event& event_info,
 					}
 				}
 
-				size_t choice = get_random() % num_choices;
+				int choice = get_random() % num_choices;
 				int tmp = 0;
 				for(size_t i = 0; i < ranges.size(); i++) {
 					tmp += (ranges[i].second - ranges[i].first) + 1;