diff --git a/package.json b/package.json
index c473c47c0..639ab1984 100644
--- a/package.json
+++ b/package.json
@@ -88,7 +88,7 @@
     "@types/sinon": "^17.0.4",
     "@types/through2": "^2.0.41",
     "c8": "^10.1.3",
-    "chai": "^4.5.0",
+    "chai": "^6.0.0",
     "chai-as-promised": "^7.1.2",
     "codecov": "^3.8.3",
     "duplexify": "^4.1.3",
diff --git a/samples/package.json b/samples/package.json
index 73df3345b..c865e4928 100644
--- a/samples/package.json
+++ b/samples/package.json
@@ -14,7 +14,7 @@
     "@google-cloud/firestore": "^8.2.0"
   },
   "devDependencies": {
-    "chai": "^4.2.0",
+    "chai": "^6.0.0",
     "mocha": "^7.0.0"
   }
 }
\ No newline at end of file