diff --git a/map.c b/map.c
index 64525ef1c9..14d948cc76 100644
--- a/map.c
+++ b/map.c
@@ -25,8 +25,9 @@ void InitMap(uint log_x, uint log_y)
 
 	DEBUG(map, 1)("Allocating map of size %dx%d", log_x, log_y);
 
-	_map_log_x = log_x;
-	_map_log_y = log_y;
+	// XXX - MSVC6 volatile workaround
+	*(volatile uint*)&_map_log_x = log_x;
+	*(volatile uint*)&_map_log_y = log_y;
 
 	map_size = MapSize();