diff --git a/package.json b/package.json
index 4899ab1..45ed051 100644
--- a/package.json
+++ b/package.json
@@ -39,12 +39,10 @@
     "mkdirp": "^1.0.4"
   },
   "devDependencies": {
-    "aegir": "^25.0.0",
+    "aegir": "^26.0.0",
     "async-iterator-all": "^1.0.0",
-    "chai": "^4.2.0",
-    "cids": "^0.8.3",
+    "cids": "^1.0.0",
     "detect-node": "^2.0.4",
-    "dirty-chai": "^2.0.1",
     "ipfs-utils": "^2.3.1",
     "memdown": "^5.1.0",
     "rimraf": "^3.0.2"
diff --git a/src/index.js b/src/index.js
index 6644ea1..ddea56c 100644
--- a/src/index.js
+++ b/src/index.js
@@ -122,7 +122,12 @@ class FsDatastore extends Adapter {
    */
   async putRaw (key, val) {
     const parts = this._encode(key)
-    const file = parts.file.slice(0, -this.opts.extension.length)
+    let file = parts.file
+
+    if (this.opts.extension.length) {
+      file = parts.file.slice(0, -this.opts.extension.length)
+    }
+
     await mkdirp(parts.dir, { fs: fs })
     await writeFile(file, val)
   }
@@ -154,7 +159,11 @@ class FsDatastore extends Adapter {
   async getRaw (key) {
     const parts = this._encode(key)
     let file = parts.file
-    file = file.slice(0, -this.opts.extension.length)
+
+    if (this.opts.extension.length) {
+      file = file.slice(0, -this.opts.extension.length)
+    }
+
     let data
     try {
       data = await fsReadFile(file)
diff --git a/test/index.spec.js b/test/index.spec.js
index 8e18a30..8670415 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -1,9 +1,7 @@
 /* eslint-env mocha */
 'use strict'
 
-const chai = require('chai')
-chai.use(require('dirty-chai'))
-const expect = chai.expect
+const { expect } = require('aegir/utils/chai')
 const path = require('path')
 const promisify = require('util').promisify
 const noop = () => {}
@@ -193,4 +191,19 @@ describe('FsDatastore', () => {
 
     expect(res).to.deep.equal(value)
   })
+
+  it('can survive putRaw and getRaw with an empty extension', async () => {
+    const dir = utils.tmpdir()
+    const fstore = new FsStore(dir, {
+      extension: ''
+    })
+    const key = new Key('CIQGFTQ7FSI2COUXWWLOQ45VUM2GUZCGAXLWCTOKKPGTUWPXHBNIVOY')
+    const value = utf8Encoder.encode('Hello world')
+
+    await fstore.putRaw(key, value)
+
+    const res = await fstore.getRaw(key)
+
+    expect(res).to.deep.equal(value)
+  })
 })