diff --git a/scripts/lib/setup-apt-repo b/scripts/lib/setup-apt-repo
index 348553d34b..159e9883d1 100755
--- a/scripts/lib/setup-apt-repo
+++ b/scripts/lib/setup-apt-repo
@@ -3,7 +3,7 @@ set -x
 
 SOURCES_FILE=/etc/apt/sources.list.d/zulip.list
 STAMP_FILE=/etc/apt/sources.list.d/zulip.list.apt-update-in-progress
-zulip_source_hash=`shasum $SOURCES_FILE`
+zulip_source_hash=`sha1sum $SOURCES_FILE`
 
 apt-get install -y lsb-release
 
@@ -32,7 +32,7 @@ else
     exit 1
 fi
 
-if [ "$zulip_source_hash" = "`shasum $SOURCES_FILE`" ] && ! [ -e "$STAMP_FILE" ]; then
+if [ "$zulip_source_hash" = "`sha1sum $SOURCES_FILE`" ] && ! [ -e "$STAMP_FILE" ]; then
     echo "zulip.list file did not change; skipping apt-get update"
 else
     # We create this stamp file to ensure `apt-get update` will be run