Index: rts/Lua/LuaZip.cpp
--- rts/Lua/LuaZip.cpp.orig
+++ rts/Lua/LuaZip.cpp
@@ -42,6 +42,10 @@
 #include <string>
 #include <vector>
 
+#ifdef __OpenBSD__
+	#include <zlib.h>
+#endif
+
 static int pushresult(lua_State* L, bool result, const char* msg)
 {
 	lua_pushboolean(L, result);
