diff --git a/externals/Makefile.am b/externals/Makefile.am
index 5d2a2324d1..32b3de78c3 100644
--- a/externals/Makefile.am
+++ b/externals/Makefile.am
@@ -1,11 +1,11 @@
 # Berkeley DB
 
-DB = db-4.4.20.NC
+DB = db-4.5.20
 
 $(DB).tar.gz:
 	@echo "Nix requires Berkeley DB to build."
 	@echo "Please download version 4.4.20 from"
-	@echo "  http://downloads.sleepycat.com/db-4.4.20.NC.tar.gz"
+	@echo "  http://download-east.oracle.com/berkeley-db/db-4.5.20.tar.gz"
 	@echo "and place it in the externals/ directory."
 	false
 
diff --git a/externals/bdb-cygwin.patch b/externals/bdb-cygwin.patch
index 3f9d658b5d..410106722a 100644
--- a/externals/bdb-cygwin.patch
+++ b/externals/bdb-cygwin.patch
@@ -1,11 +1,11 @@
-diff -rc db-4.4.20.NC-old/os/os_flock.c db-4.4.20.NC/os/os_flock.c
-*** db-4.4.20.NC-old/os/os_flock.c	Mon Jun 20 16:59:01 2005
---- db-4.4.20.NC/os/os_flock.c	Wed Jun  7 17:01:49 2006
+diff -rc db-4.5.20-orig/os/os_flock.c db-4.5.20/os/os_flock.c
+*** db-4.5.20-orig/os/os_flock.c	2006-10-13 12:36:12.000000000 +0200
+--- db-4.5.20/os/os_flock.c	2006-10-13 12:40:11.000000000 +0200
 ***************
-*** 36,41 ****
---- 36,50 ----
+*** 30,35 ****
+--- 30,44 ----
   
-  	DB_ASSERT(F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
+  	DB_ASSERT(dbenv, F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
   
 + #ifdef __CYGWIN__
 + 	/*
@@ -16,6 +16,7 @@ diff -rc db-4.4.20.NC-old/os/os_flock.c db-4.4.20.NC/os/os_flock.c
 + 	offset += (off_t) 1 << 62;
 + #endif
 + 
-  #ifdef HAVE_FCNTL
   	fl.l_start = offset;
   	fl.l_len = 1;
+  	fl.l_type = acquire ? F_WRLCK : F_UNLCK;
+Only in db-4.5.20/os: os_flock.c~