diff --git a/.github/workflows/ci.yml b/.github/workflows/ch1.yml
similarity index 64%
rename from .github/workflows/ci.yml
rename to .github/workflows/ch1.yml
index 8a59a1f..c086c6a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ch1.yml
@@ -1,11 +1,17 @@
 #
-# ci.yml
-#
 # Run tests for all pushed commits and opened pull requests on Github.
 #
 
-name: CI
-on: [push, pull_request]
+name: CH1 Test
+on:
+  push:
+    paths:
+      - 'src/CH1Message.ts'
+      - 'src/CH1Message.test.ts'
+  pull_request:
+    paths:
+      - 'src/CH1Message.ts'
+      - 'src/CH1Message.test.ts'
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -14,13 +20,13 @@ jobs:
       - name: Set up NodeJS
         uses: actions/setup-node@v4
         with:
-          node-version: '16'
+          node-version: '18'
       - name: Git checkout
         uses: actions/checkout@v4
       - name: NPM ci, build, & test
         run: |
           npm install
           npm run build --if-present
-          npm test
+          npm test -t CH1
         env:
           CI: true
diff --git a/src/MessageCH1.test.ts b/src/CH1Message.test.ts
similarity index 98%
rename from src/MessageCH1.test.ts
rename to src/CH1Message.test.ts
index e0a6b0e..9cecacd 100644
--- a/src/MessageCH1.test.ts
+++ b/src/CH1Message.test.ts
@@ -1,5 +1,5 @@
-import { MessageContract, Message} from './MessageCH1'
-import { Gadgets, Field, Mina, PrivateKey, PublicKey, AccountUpdate, MerkleMap, Poseidon } from 'o1js';
+import { MessageContract, Message} from './CH1Message'
+import { Gadgets, Field, Mina, PrivateKey, PublicKey, AccountUpdate, MerkleMap } from 'o1js';
 
 let proofsEnabled = false;
 
diff --git a/src/MessageCH1.ts b/src/CH1Message.ts
similarity index 100%
rename from src/MessageCH1.ts
rename to src/CH1Message.ts
diff --git a/src/index.ts b/src/index.ts
index 838aabe..2d15fef 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,3 @@
-import { MessageContract } from './MessageCH1.js';
+import { MessageContract } from './CH1Message.js';
 
 export { MessageContract };