diff --git a/contrib/check-pytype.sh b/contrib/check-pytype.sh
--- a/contrib/check-pytype.sh
+++ b/contrib/check-pytype.sh
@@ -1,7 +1,8 @@
-#!/bin/sh
+#!/bin/bash
 
 set -e
 set -u
+set -o pipefail
 
 cd "$(hg root)"
 
diff --git a/contrib/heptapod-ci.yml b/contrib/heptapod-ci.yml
--- a/contrib/heptapod-ci.yml
+++ b/contrib/heptapod-ci.yml
@@ -442,7 +442,7 @@ check-pytype:
       - ./contrib/setup-pytype.sh
     script:
       - echo "Entering script section"
-      - sh contrib/check-pytype.sh
+      - bash contrib/check-pytype.sh
 
 # `sh.exe --login` sets a couple of extra environment variables that are defined
 # in the MinGW shell, but switches CWD to /home/$username.  The previous value