diff --git a/dev-requirements.txt b/dev-requirements.txt
index 8f40728..d360e0e 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,4 +1,5 @@
 pytest
 pytest-cov
 pytest-flakes
-pytest-benchmark==3.2.2
\ No newline at end of file
+pytest-benchmark==3.2.2
+sphinx