diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 207994e..74cb754 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,6 +1,6 @@
 name: esbuild-jest
 
-on: [push]
+on: [push, pull_request]
 
 jobs:
   ubuntu-latest:
@@ -19,6 +19,7 @@ jobs:
     - run: yarn
     - run: yarn build
     - run: yarn test
+    - run: yarn test:coverage
       env:
         CI: true
   windows-latest:
@@ -37,6 +38,7 @@ jobs:
     - run: yarn
     - run: yarn build
     - run: yarn test
+    - run: yarn test:coverage
       env:
         CI: true
   macos-latest:
@@ -55,5 +57,6 @@ jobs:
     - run: yarn
     - run: yarn build
     - run: yarn test
+    - run: yarn test:coverage
       env:
         CI: true
diff --git a/.gitignore b/.gitignore
index c93c40f..4277722 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 node_modules
 dist
 .envrc
-default.nix
\ No newline at end of file
+default.nix
+coverage
\ No newline at end of file
diff --git a/package.json b/package.json
index c456524..8c87d25 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,8 @@
   "scripts": {
     "postinstall": "yarn build",
     "build": "ts-node ./tools/build.ts",
-    "test": "jest --clearCache && jest --detectOpenHandles"
+    "test": "jest --clearCache && jest --detectOpenHandles",
+    "test:coverage": "jest --clearCache && jest --coverage"
   },
   "repository": {
     "type": "git",
diff --git a/src/index.ts b/src/index.ts
index 12501db..a58c604 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -17,7 +17,7 @@ const createTransformer = (options?: Options) => ({
     const ext = getExt(filename), extName = extname(filename).slice(1)
 
     // Caution: disabling this, can cause issues with inlineSnapshots since can't find the original line
-    const enableSourcemaps = options?.sourcemap || true
+    const enableSourcemaps = options?.sourcemap === false ? false : (options?.sourcemap || true)
     const loader = (options?.loaders && options?.loaders[ext]
       ? options.loaders[ext]
       : loaders.includes(extName) ? extName: 'text'