diff --git a/packages/core/package.json b/packages/core/package.json
index 089c2919..1b312a87 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -40,7 +40,7 @@
   "devDependencies": {
     "@briancavalier/assert": "^3.2.0",
     "@istanbuljs/nyc-config-typescript": "^1.0.0",
-    "@types/mocha": "^5.2.7",
+    "@types/mocha": "^8.0.3",
     "@typescript-eslint/eslint-plugin": "^1.11.0",
     "@typescript-eslint/parser": "^1.11.0",
     "cpy-cli": "^3.0.0",
diff --git a/packages/disposable/package-lock.json b/packages/disposable/package-lock.json
index ce93b9bf..e921bac3 100644
--- a/packages/disposable/package-lock.json
+++ b/packages/disposable/package-lock.json
@@ -399,9 +399,9 @@
 			"dev": true
 		},
 		"@types/mocha": {
-			"version": "5.2.7",
-			"resolved": "https://registry.npmjs.org/@types/mocha/-/mocha-5.2.7.tgz",
-			"integrity": "sha512-NYrtPht0wGzhwe9+/idPaBB+TqkY9AhTvOLMkThm0IoEfLaiVQZwBwyJ5puCkO3AUCWrmcoePjp2mbFocKy4SQ==",
+			"version": "8.0.3",
+			"resolved": "https://registry.npmjs.org/@types/mocha/-/mocha-8.0.3.tgz",
+			"integrity": "sha512-vyxR57nv8NfcU0GZu8EUXZLTbCMupIUwy95LJ6lllN+JRPG25CwMHoB1q5xKh8YKhQnHYRAn4yW2yuHbf/5xgg==",
 			"dev": true
 		},
 		"@types/node": {
diff --git a/packages/disposable/package.json b/packages/disposable/package.json
index a144484d..46002c7d 100644
--- a/packages/disposable/package.json
+++ b/packages/disposable/package.json
@@ -40,7 +40,7 @@
   "devDependencies": {
     "@briancavalier/assert": "^3.2.0",
     "@istanbuljs/nyc-config-typescript": "^1.0.0",
-    "@types/mocha": "^5.2.7",
+    "@types/mocha": "^8.0.3",
     "@types/sinon": "^7.5.1",
     "@typescript-eslint/eslint-plugin": "^1.11.0",
     "@typescript-eslint/parser": "^1.11.0",
diff --git a/packages/prelude/package.json b/packages/prelude/package.json
index 49c0543b..2e73acc2 100644
--- a/packages/prelude/package.json
+++ b/packages/prelude/package.json
@@ -32,7 +32,7 @@
   "devDependencies": {
     "@istanbuljs/nyc-config-typescript": "^1.0.0",
     "@types/assert": "1.4.6",
-    "@types/mocha": "^5.2.7",
+    "@types/mocha": "^8.0.3",
     "@typescript-eslint/eslint-plugin": "^1.11.0",
     "@typescript-eslint/parser": "^1.11.0",
     "cpy-cli": "^3.0.0",
diff --git a/packages/scheduler/package.json b/packages/scheduler/package.json
index de0c72c5..f8277f55 100644
--- a/packages/scheduler/package.json
+++ b/packages/scheduler/package.json
@@ -40,7 +40,7 @@
   "devDependencies": {
     "@briancavalier/assert": "^3.2.0",
     "@istanbuljs/nyc-config-typescript": "^1.0.0",
-    "@types/mocha": "^5.2.7",
+    "@types/mocha": "^8.0.3",
     "@typescript-eslint/eslint-plugin": "^1.11.0",
     "@typescript-eslint/parser": "^1.11.0",
     "cpy-cli": "^3.0.0",