diff --git a/services/document-updater/.nvmrc b/services/document-updater/.nvmrc
index 2baa2d433a..e68b860383 100644
--- a/services/document-updater/.nvmrc
+++ b/services/document-updater/.nvmrc
@@ -1 +1 @@
-10.23.1
+12.21.0
diff --git a/services/document-updater/Dockerfile b/services/document-updater/Dockerfile
index 2da67d2436..4f417a2a4b 100644
--- a/services/document-updater/Dockerfile
+++ b/services/document-updater/Dockerfile
@@ -2,7 +2,7 @@
 # Instead run bin/update_build_scripts from
 # https://github.com/sharelatex/sharelatex-dev-environment
 
-FROM node:10.23.1 as base
+FROM node:12.21.0 as base
 
 WORKDIR /app
 
diff --git a/services/document-updater/Makefile b/services/document-updater/Makefile
index 596aa47fdb..7591d2a689 100644
--- a/services/document-updater/Makefile
+++ b/services/document-updater/Makefile
@@ -21,8 +21,10 @@ DOCKER_COMPOSE_TEST_UNIT = \
 	COMPOSE_PROJECT_NAME=test_unit_$(BUILD_DIR_NAME) $(DOCKER_COMPOSE)
 
 clean:
-	docker rmi ci/$(PROJECT_NAME):$(BRANCH_NAME)-$(BUILD_NUMBER)
-	docker rmi gcr.io/overleaf-ops/$(PROJECT_NAME):$(BRANCH_NAME)-$(BUILD_NUMBER)
+	-docker rmi ci/$(PROJECT_NAME):$(BRANCH_NAME)-$(BUILD_NUMBER)
+	-docker rmi gcr.io/overleaf-ops/$(PROJECT_NAME):$(BRANCH_NAME)-$(BUILD_NUMBER)
+	-$(DOCKER_COMPOSE_TEST_UNIT) down --rmi local
+	-$(DOCKER_COMPOSE_TEST_ACCEPTANCE) down --rmi local
 
 format:
 	$(DOCKER_COMPOSE) run --rm test_unit npm run --silent format
diff --git a/services/document-updater/app/js/RangesTracker.js b/services/document-updater/app/js/RangesTracker.js
index 6107acf300..5991ee2993 100644
--- a/services/document-updater/app/js/RangesTracker.js
+++ b/services/document-updater/app/js/RangesTracker.js
@@ -706,8 +706,10 @@ const load = function () {
           return result
         } else if (c1.op.i != null && c2.op.d != null) {
           return 1
-        } else {
+        } else if (c1.op.d != null && c2.op.i != null) {
           return -1
+        } else {
+          return 0
         }
       })
 
@@ -728,8 +730,10 @@ const load = function () {
           return result
         } else if (a.i != null && b.d != null) {
           return 1
-        } else {
+        } else if (a.d != null && b.i != null) {
           return -1
+        } else {
+          return 0
         }
       })
 
diff --git a/services/document-updater/buildscript.txt b/services/document-updater/buildscript.txt
index 0d8b15d9f5..2d2f00495e 100644
--- a/services/document-updater/buildscript.txt
+++ b/services/document-updater/buildscript.txt
@@ -3,6 +3,6 @@ document-updater
 --docker-repos=gcr.io/overleaf-ops
 --env-add=
 --env-pass-through=
---node-version=10.23.1
+--node-version=12.21.0
 --public-repo=True
---script-version=3.4.0
+--script-version=3.7.0
diff --git a/services/document-updater/docker-compose.yml b/services/document-updater/docker-compose.yml
index 0db448f9b5..6a1c097a30 100644
--- a/services/document-updater/docker-compose.yml
+++ b/services/document-updater/docker-compose.yml
@@ -6,7 +6,7 @@ version: "2.3"
 
 services:
   test_unit:
-    image: node:10.23.1
+    image: node:12.21.0
     volumes:
       - .:/app
     working_dir: /app
@@ -18,7 +18,7 @@ services:
     user: node
 
   test_acceptance:
-    image: node:10.23.1
+    image: node:12.21.0
     volumes:
       - .:/app
     working_dir: /app