diff --git a/package.json b/package.json
index cb7c8a4..17f6973 100644
--- a/package.json
+++ b/package.json
@@ -142,7 +142,8 @@
     "@libp2p/interface-metrics": "^4.0.0"
   },
   "devDependencies": {
-    "aegir": "^37.0.7",
+    "@types/sinon": "^10.0.15",
+    "aegir": "^39.0.10",
     "sinon": "^15.0.1",
     "sinon-ts": "^1.0.0"
   }
diff --git a/src/index.ts b/src/index.ts
index da948c4..6cf3fa3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -17,24 +17,24 @@ class TrackedMap<K, V> extends Map<K, V> {
     this.updateComponentMetric()
   }
 
-  set (key: K, value: V) {
+  set (key: K, value: V): this {
     super.set(key, value)
     this.updateComponentMetric()
     return this
   }
 
-  delete (key: K) {
+  delete (key: K): boolean {
     const deleted = super.delete(key)
     this.updateComponentMetric()
     return deleted
   }
 
-  clear () {
+  clear (): void {
     super.clear()
     this.updateComponentMetric()
   }
 
-  private updateComponentMetric () {
+  private updateComponentMetric (): void {
     this.metric.update(this.size)
   }
 }
diff --git a/test/index.spec.ts b/test/index.spec.ts
index d6f38b5..4450f41 100644
--- a/test/index.spec.ts
+++ b/test/index.spec.ts
@@ -1,8 +1,8 @@
 import { expect } from 'aegir/chai'
+import { stubInterface } from 'sinon-ts'
 import { trackedMap } from '../src/index.js'
-import type { SinonStubbedInstance } from 'sinon'
 import type { Metric, Metrics } from '@libp2p/interface-metrics'
-import { stubInterface } from 'sinon-ts'
+import type { SinonStubbedInstance } from 'sinon'
 
 describe('tracked-map', () => {
   let metrics: SinonStubbedInstance<Metrics>