diff --git a/eslint.config.mjs b/eslint.config.mjs
index 71732a6..dd30487 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -1,5 +1,15 @@
 import config from "eslint-config-agent";
 
+// Require strict equality (`===`/`!==`) everywhere. Loose `==`/`!=` perform
+// implicit type coercion (e.g. `0 == ""`, `null == undefined`), which hides
+// type bugs behind surprising truthiness rules. Strict equality keeps comparisons
+// predictable and type-safe.
+const strictEqualityRule = {
+  rules: {
+    eqeqeq: ["error", "always"],
+  },
+};
+
 // URL strings are centralized in these files; all other src files must reference these constants.
 const urlConstantsOverride = {
   files: ["src/lib/github-url.ts", "src/lib/runner-url.ts", "src/lib/analytics-script-url.ts", "src/lib/jira-webhook-url.ts"],
@@ -8,4 +18,4 @@ const urlConstantsOverride = {
   },
 };
 
-export default [...config, urlConstantsOverride];
+export default [...config, strictEqualityRule, urlConstantsOverride];