diff --git a/sites/scrapy.org/Makefile b/sites/scrapy.org/Makefile
index 72f355f93..75a2e7a3c 100644
--- a/sites/scrapy.org/Makefile
+++ b/sites/scrapy.org/Makefile
@@ -9,7 +9,7 @@ all : build tests
 build : docs
 
 docs :
-	sphinx-build -a -b pickle docs/scrapy-docs docs/pickle
+	sphinx-build -E -a -b pickle docs/scrapy-docs docs/pickle
 
 tests :
 	$(SETTINGS); \