diff --git a/Doc/Makefile b/Doc/Makefile
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -60,7 +60,7 @@
 
 build: checkout
 	mkdir -p build/$(BUILDER) build/doctrees
-	$(PYTHON) tools/sphinx-build.py $(ALLSPHINXOPTS)
+	$(PYTHON) tools/sphinx-build.py $(ALLSPHINXOPTS); if [ $(BUILDER) != suspicious -a $$? -ne 0 ] ; then exit $$? ; fi
 	@echo
 
 html: BUILDER = html