diff --git a/docbook/Makefile.nmake b/docbook/Makefile.nmake
index 3212efc64c..de73a91581 100644
--- a/docbook/Makefile.nmake
+++ b/docbook/Makefile.nmake
@@ -10,6 +10,7 @@
 
 ############### YOU SHOULDN'T HAVE TO EDIT ANYTHING BELOW THIS LINE! ################
 
+TOOLS_DIR=..\tools
 include ..\config.nmake
 include Makefile.common