diff --git a/contrib/setup-pytype.sh b/contrib/setup-pytype.sh
new file mode 100755
--- /dev/null
+++ b/contrib/setup-pytype.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -e
+set -u
+
+# Find the python3 setup that would run pytype
+PYTYPE=`which pytype`
+PYTHON3=`head -n1 ${PYTYPE} | sed -s 's/#!//'`
+
+# Existing stubs that pytype processes live here
+TYPESHED=$(${PYTHON3} -c "import pytype; print(pytype.__path__[0])")/typeshed/stubs
+HG_STUBS=${TYPESHED}/mercurial
+
+echo "Patching typeshed at $HG_STUBS"
+
+rm -rf ${HG_STUBS}
+mkdir -p ${HG_STUBS}
+
+cat > ${HG_STUBS}/METADATA.toml <<EOF
+version = "0.1"
+EOF
+
+
+mkdir -p ${HG_STUBS}/mercurial/cext ${HG_STUBS}/mercurial/thirdparty/attr
+
+touch ${HG_STUBS}/mercurial/__init__.pyi
+touch ${HG_STUBS}/mercurial/cext/__init__.pyi
+touch ${HG_STUBS}/mercurial/thirdparty/__init__.pyi
+
+ln -sf $(hg root)/mercurial/cext/*.{pyi,typed} \
+       ${HG_STUBS}/mercurial/cext
+ln -sf $(hg root)/mercurial/thirdparty/attr/*.{pyi,typed} \
+       ${HG_STUBS}/mercurial/thirdparty/attr