diff --git a/doc/requirements.txt b/doc/requirements.txt
old mode 100755
new mode 100644
index e3059c04..32991776
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,3 +1,3 @@
 sphinx==1.2.3
-mercurial==3.2.2
+mercurial==4.1.3
 sphinx-patchqueue==0.4.0