diff --git a/.travis.yml b/.travis.yml
index 737a0ee..5d80ba2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,6 @@ node_js:
   - "10"
   - "9"
   - "8"
-  - "6"
 
 install:
   - npm set audit false
diff --git a/packages/hast-util-from-webparser/jest.config.js b/packages/hast-util-from-webparser/jest.config.js
index 569d762..4dc3e30 100644
--- a/packages/hast-util-from-webparser/jest.config.js
+++ b/packages/hast-util-from-webparser/jest.config.js
@@ -8,6 +8,6 @@ module.exports = {
   transform: {
     '^.+\\.(ts|tsx)$': 'ts-jest'
   },
-  testMatch: ['**/test/**/*.test.(ts|js)', '**/__snapshot__/**/*.snap'],
+  testMatch: ['**/test/**/*.test.ts', '**/__snapshot__/**/*.snap'],
   testEnvironment: 'node'
 }
diff --git a/packages/rehype-webparser/jest.config.js b/packages/rehype-webparser/jest.config.js
index bfd7676..7b91600 100644
--- a/packages/rehype-webparser/jest.config.js
+++ b/packages/rehype-webparser/jest.config.js
@@ -8,6 +8,6 @@ module.exports = {
   transform: {
     '^.+\\.(ts|tsx)$': 'ts-jest'
   },
-  testMatch: ['**/test/**/*.test.(ts|js)'],
+  testMatch: ['**/test/**/*.test.ts'],
   testEnvironment: 'node'
 }
diff --git a/packages/webparser/jest.config.js b/packages/webparser/jest.config.js
index bfd7676..7b91600 100644
--- a/packages/webparser/jest.config.js
+++ b/packages/webparser/jest.config.js
@@ -8,6 +8,6 @@ module.exports = {
   transform: {
     '^.+\\.(ts|tsx)$': 'ts-jest'
   },
-  testMatch: ['**/test/**/*.test.(ts|js)'],
+  testMatch: ['**/test/**/*.test.ts'],
   testEnvironment: 'node'
 }