diff -r 57c68b3af2ea -r 193cf2fa692a src/HOL/IsaMakefile
--- a/src/HOL/IsaMakefile	Wed Mar 11 10:58:18 2009 +0100
+++ b/src/HOL/IsaMakefile	Wed Mar 11 11:41:14 2009 +0100
@@ -692,7 +692,7 @@
 
 $(LOG)/HOL-Docs.gz: $(OUT)/HOL Docs/Main_Doc.thy Docs/ROOT.ML	\
   Docs/document/root.tex
-	@$(ISABELLE_TOOL) usedir $(OUT)/HOL Docs
+	@$(ISABELLE_TOOL) usedir -D generated $(OUT)/HOL Docs
 
 
 ## HOL-Lambda