diff --git a/Makefile b/Makefile
index 965d42c4fde49c48b779d6c9921d1507ddee4cde..dfa203db57760417f87a375d279972a0835655bf 100644
--- a/Makefile
+++ b/Makefile
@@ -32,7 +32,8 @@ test-code: in
 	$(NOSETESTS) -s sklearn
 test-doc:
 	$(NOSETESTS) -s --with-doctest --doctest-tests --doctest-extension=rst \
-	--doctest-fixtures=_fixture doc/ doc/modules/ doc/developers
+	--doctest-extension=inc --doctest-fixtures=_fixture doc/ doc/modules/ \
+	doc/developers
 
 test-coverage:
 	$(NOSETESTS) -s --with-coverage --cover-html --cover-html-dir=coverage \
diff --git a/doc/datasets/labeled_faces.txt b/doc/datasets/labeled_faces.inc
similarity index 100%
rename from doc/datasets/labeled_faces.txt
rename to doc/datasets/labeled_faces.inc
diff --git a/doc/datasets/mldata.txt b/doc/datasets/mldata.inc
similarity index 100%
rename from doc/datasets/mldata.txt
rename to doc/datasets/mldata.inc
diff --git a/doc/datasets/olivetti_faces.txt b/doc/datasets/olivetti_faces.inc
similarity index 100%
rename from doc/datasets/olivetti_faces.txt
rename to doc/datasets/olivetti_faces.inc
diff --git a/doc/datasets/twenty_newsgroups.txt b/doc/datasets/twenty_newsgroups.inc
similarity index 100%
rename from doc/datasets/twenty_newsgroups.txt
rename to doc/datasets/twenty_newsgroups.inc