diff --git a/CHANGELOG.md b/CHANGELOG.md
index b451786..5314477 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Test-only module mocks no longer leak into later integration tests when the full
   suite runs in one Bun process.
 
+### Changed
+- Enabled TypeScript checks for implicit returns and switch fallthrough.
+
 ## [0.2.0] - 2026-07-27
 
 ### Removed
diff --git a/tsconfig.json b/tsconfig.json
index 8207828..ec7cf4a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,6 +5,8 @@
     "moduleResolution": "bundler",
     "lib": ["ESNext"],
     "strict": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true,
     "noUncheckedIndexedAccess": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,