diff --git a/Makefile b/Makefile
index b48f1e2..098fe2f 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    =
+SPHINXOPTS    = -Ea
 SPHINXBUILD   = sphinx-build
 SPHINXPROJ    = AgaricCollective
 SOURCEDIR     = .