diff --git a/lib/copy-sync/__tests__/copy-sync-preserve-timestamp.test.js b/lib/copy-sync/__tests__/copy-sync-preserve-timestamp.test.js
index da3aacac..6612b3c9 100644
--- a/lib/copy-sync/__tests__/copy-sync-preserve-timestamp.test.js
+++ b/lib/copy-sync/__tests__/copy-sync-preserve-timestamp.test.js
@@ -3,6 +3,7 @@
 const fs = require('../../')
 const os = require('os')
 const path = require('path')
+const copySync = require('../copy-sync')
 const utimesSync = require('../../util/utimes').utimesMillisSync
 const assert = require('assert')
 const semver = require('semver')
@@ -48,7 +49,7 @@ describeIfPractical('copySync() - preserveTimestamps option', () => {
         beforeEach(() => setupFixture(params.readonly))
 
         it('should have the same timestamps on copy', () => {
-          fs.copySync(SRC, DEST, { preserveTimestamps: true })
+          copySync(SRC, DEST, { preserveTimestamps: true })
           FILES.forEach(testFile({ preserveTimestamps: true }))
         })
       })
@@ -63,10 +64,10 @@ describeIfPractical('copySync() - preserveTimestamps option', () => {
       const toStat = fs.statSync(b)
       if (options.preserveTimestamps) {
         // Windows sub-second precision fixed: https://github.com/nodejs/io.js/issues/2069
-        assert.strictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime())
-        assert.strictEqual(toStat.atime.getTime(), fromStat.atime.getTime())
+        assert.strictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime(), 'different mtime values')
+        assert.strictEqual(toStat.atime.getTime(), fromStat.atime.getTime(), 'different atime values')
       } else {
-        assert.notStrictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime())
+        assert.notStrictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime(), 'same mtime values')
         // the access time might actually be the same, so check only modification time
       }
     }
diff --git a/lib/copy-sync/__tests__/copyfilesync-fallback.test.js b/lib/copy-sync/__tests__/copyfilesync-fallback.test.js
index f6bdb269..7a619a3f 100644
--- a/lib/copy-sync/__tests__/copyfilesync-fallback.test.js
+++ b/lib/copy-sync/__tests__/copyfilesync-fallback.test.js
@@ -1,26 +1,25 @@
-const fs = require('fs')
+const fs = require('../../')
 const path = require('path')
 
-/* global after, describe */
+/* global describe */
 
 if (typeof fs.copyFileSync === 'function') {
-  // Re-run all copySync tests without fs.copyFileSync
+  // Also load copy-sync tests without fs.copyFileSync
   describe('> when using copyFileSyncFallback', () => {
     const originalCopyFile = fs.copyFileSync
 
-    after(done => {
-      fs.copyFileSync = originalCopyFile
-      done()
-    })
-
     delete fs.copyFileSync
     const fallbackTest = path.basename(__filename)
-    fs.readdirSync(__dirname)
-      .filter(filename => filename.endsWith('.test.js') && filename !== fallbackTest)
-      .map(filename => {
-        const testModule = `./${filename}`
-        delete require.cache[require.resolve(testModule)]
-        require(testModule)
-      })
+    try {
+      fs.readdirSync(__dirname)
+        .filter(filename => filename.endsWith('.test.js') && filename !== fallbackTest)
+        .map(filename => {
+          const testModule = `./${filename}`
+          delete require.cache[require.resolve(testModule)]
+          require(testModule)
+        })
+    } finally {
+      fs.copyFileSync = originalCopyFile
+    }
   })
 }
diff --git a/lib/copy/__tests__/copy-preserve-timestamp.test.js b/lib/copy/__tests__/copy-preserve-timestamp.test.js
index 6fd0b173..5447e706 100644
--- a/lib/copy/__tests__/copy-preserve-timestamp.test.js
+++ b/lib/copy/__tests__/copy-preserve-timestamp.test.js
@@ -67,10 +67,10 @@ describeIfPractical('copy() - preserve timestamp', () => {
       const toStat = fs.statSync(b)
       if (options.preserveTimestamps) {
         // Windows sub-second precision fixed: https://github.com/nodejs/io.js/issues/2069
-        assert.strictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime())
-        assert.strictEqual(toStat.atime.getTime(), fromStat.atime.getTime())
+        assert.strictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime(), 'different mtime values')
+        assert.strictEqual(toStat.atime.getTime(), fromStat.atime.getTime(), 'different atime values')
       } else {
-        assert.notStrictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime())
+        assert.notStrictEqual(toStat.mtime.getTime(), fromStat.mtime.getTime(), 'same mtime values')
         // the access time might actually be the same, so check only modification time
       }
     }
diff --git a/lib/copy/__tests__/copyfile-fallback.test.js b/lib/copy/__tests__/copyfile-fallback.test.js
index 45979494..d32d57ba 100644
--- a/lib/copy/__tests__/copyfile-fallback.test.js
+++ b/lib/copy/__tests__/copyfile-fallback.test.js
@@ -1,26 +1,25 @@
-const fs = require('fs')
+const fs = require('../../')
 const path = require('path')
 
-/* global after, describe */
+/* global describe */
 
 if (typeof fs.copyFile === 'function') {
-  // Re-run all copy tests without fs.copyFile
+  // Also load copy tests without fs.copyFile
   describe('> when using copyFileFallback', () => {
     const originalCopyFile = fs.copyFile
 
-    after(done => {
-      fs.copyFile = originalCopyFile
-      done()
-    })
-
     delete fs.copyFile
     const fallbackTest = path.basename(__filename)
-    fs.readdirSync(__dirname)
-      .filter(filename => filename.endsWith('.test.js') && filename !== fallbackTest)
-      .map(filename => {
-        const testModule = `./${filename}`
-        delete require.cache[require.resolve(testModule)]
-        require(testModule)
-      })
+    try {
+      fs.readdirSync(__dirname)
+        .filter(filename => filename.endsWith('.test.js') && filename !== fallbackTest)
+        .map(filename => {
+          const testModule = `./${filename}`
+          delete require.cache[require.resolve(testModule)]
+          require(testModule)
+        })
+    } finally {
+      fs.copyFile = originalCopyFile
+    }
   })
 }