--- BDB/BDB.xs	2007/02/11 22:38:37	1.9
+++ BDB/BDB.xs	2007/03/05 19:47:01	1.10
@@ -27,6 +27,10 @@
 
 #include <db.h>
 
+#if DB_VERSION_MAJOR < 4 || (DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR < 5)
+# error you need Berkeley DB 4.5 or newer installed
+#endif
+
 /* number of seconds after which idle threads exit */
 #define IDLE_TIMEOUT 10