diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp.git/HEAD b/__tests__/__fixtures__/test-GitIndex-timestamp.git/HEAD
new file mode 100644
index 000000000..b870d8262
--- /dev/null
+++ b/__tests__/__fixtures__/test-GitIndex-timestamp.git/HEAD
@@ -0,0 +1 @@
+ref: refs/heads/main
diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp.git/index b/__tests__/__fixtures__/test-GitIndex-timestamp.git/index
new file mode 100644
index 000000000..87d898f67
Binary files /dev/null and b/__tests__/__fixtures__/test-GitIndex-timestamp.git/index differ
diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/00/a1ba6b231e31f71e9bfd2289c9c43a561941a6 b/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/00/a1ba6b231e31f71e9bfd2289c9c43a561941a6
new file mode 100644
index 000000000..d4cbb2143
Binary files /dev/null and b/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/00/a1ba6b231e31f71e9bfd2289c9c43a561941a6 differ
diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/3f/c971f7905cacaba1c1dc2b9359c51b6e53f2f6 b/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/3f/c971f7905cacaba1c1dc2b9359c51b6e53f2f6
new file mode 100644
index 000000000..b093327e1
Binary files /dev/null and b/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/3f/c971f7905cacaba1c1dc2b9359c51b6e53f2f6 differ
diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/86/6e7d65b24e0cdb9d0630c0fb4c43f69f8dc420 b/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/86/6e7d65b24e0cdb9d0630c0fb4c43f69f8dc420
new file mode 100644
index 000000000..dc1a04c1b
Binary files /dev/null and b/__tests__/__fixtures__/test-GitIndex-timestamp.git/objects/86/6e7d65b24e0cdb9d0630c0fb4c43f69f8dc420 differ
diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp.git/refs/heads/main b/__tests__/__fixtures__/test-GitIndex-timestamp.git/refs/heads/main
new file mode 100644
index 000000000..2d4f23c3f
--- /dev/null
+++ b/__tests__/__fixtures__/test-GitIndex-timestamp.git/refs/heads/main
@@ -0,0 +1 @@
+866e7d65b24e0cdb9d0630c0fb4c43f69f8dc420
diff --git a/__tests__/__fixtures__/test-GitIndex-timestamp/nano.txt b/__tests__/__fixtures__/test-GitIndex-timestamp/nano.txt
new file mode 100644
index 000000000..00a1ba6b2
--- /dev/null
+++ b/__tests__/__fixtures__/test-GitIndex-timestamp/nano.txt
@@ -0,0 +1 @@
+validate nanoseconds
\ No newline at end of file
diff --git a/__tests__/test-GitIndex.js b/__tests__/test-GitIndex.js
index 3520d2cf1..e4aa0491f 100644
--- a/__tests__/test-GitIndex.js
+++ b/__tests__/test-GitIndex.js
@@ -4,6 +4,8 @@ const path = require('path')
 
 const { GitIndex, GitIndexManager } = require('isomorphic-git/internal-apis')
 
+const { normalizeStats } = require('../src/utils/normalizeStats.js')
+
 const { makeFixture } = require('./__helpers__/FixtureFS.js')
 
 describe('GitIndex', () => {
@@ -128,4 +130,27 @@ describe('GitIndex', () => {
     expect(ctimeSeconds).not.toBeNull()
     expect(ctimeNanoseconds).not.toBeNull()
   })
+
+  it('ensure nanoseconds of files are equal with index', async () => {
+    const { fs, gitdir } = await makeFixture('test-GitIndex-timestamp')
+    const buffer = await fs.read(path.join(gitdir, 'index'))
+    const index = await GitIndex.from(buffer)
+
+    const stats = normalizeStats(
+      await fs.lstat('__tests__/__fixtures__/test-GitIndex-timestamp/nano.txt')
+    )
+
+    expect(index.entriesMap.get('nano.txt').ctimeSeconds).toEqual(
+      stats.ctimeSeconds
+    )
+    expect(index.entriesMap.get('nano.txt').ctimeNanoseconds).toEqual(
+      stats.ctimeNanoseconds
+    )
+    expect(index.entriesMap.get('nano.txt').mtimeSeconds).toEqual(
+      stats.mtimeSeconds
+    )
+    expect(index.entriesMap.get('nano.txt').mtimeNanoseconds).toEqual(
+      stats.mtimeNanoseconds
+    )
+  })
 })