Keep testing against node 4 on 2.2.x
diff --git a/.travis.yml b/.travis.yml
index 25b631d..b4e310d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,7 @@
 git:
   depth: 10
 node_js:
+  - "4"
   - "6"
   - "8"
   - "10"
diff --git a/appveyor.yml b/appveyor.yml
index f34dfbd..5302ae0 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -3,6 +3,7 @@
 
 environment:
   matrix:
+  - nodejs_version: "4"
   - nodejs_version: "6"
   - nodejs_version: "8"
   - nodejs_version: "10"