diff --git a/packages/ensnode-sdk/src/registrars/registration-expiration.test.ts b/packages/ensnode-sdk/src/registrars/registration-expiration.test.ts
new file mode 100644
index 0000000000..35c9294103
--- /dev/null
+++ b/packages/ensnode-sdk/src/registrars/registration-expiration.test.ts
@@ -0,0 +1,67 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  isRegistrationExpired,
+  isRegistrationFullyExpired,
+  isRegistrationInGracePeriod,
+} from "./registration-expiration";
+
+describe("registration expiration", () => {
+  const expiry = 1000n;
+  const gracePeriod = 100n;
+
+  describe("isRegistrationExpired", () => {
+    it.each([
+      { now: 999n, expected: false, description: "before expiry" },
+      { now: 1000n, expected: true, description: "at expiry" },
+      { now: 1001n, expected: true, description: "after expiry" },
+    ])("returns $expected when $description", ({ now, expected }) => {
+      expect(isRegistrationExpired({ expiry, gracePeriod }, now)).toBe(expected);
+    });
+
+    it("returns false when expiry is null", () => {
+      expect(isRegistrationExpired({ expiry: null, gracePeriod }, 2000n)).toBe(false);
+    });
+  });
+
+  describe("isRegistrationFullyExpired", () => {
+    it.each([
+      { now: 999n, expected: false, description: "before expiry" },
+      { now: 1000n, expected: false, description: "at expiry" },
+      { now: 1050n, expected: false, description: "during grace period" },
+      { now: 1100n, expected: false, description: "at expiry + grace period" },
+      { now: 1101n, expected: true, description: "after expiry + grace period" },
+    ])("returns $expected when $description", ({ now, expected }) => {
+      expect(isRegistrationFullyExpired({ expiry, gracePeriod }, now)).toBe(expected);
+    });
+
+    it("returns false when expiry is null", () => {
+      expect(isRegistrationFullyExpired({ expiry: null, gracePeriod }, 2000n)).toBe(false);
+    });
+
+    it("treats null grace period as zero", () => {
+      expect(isRegistrationFullyExpired({ expiry, gracePeriod: null }, 1000n)).toBe(false);
+      expect(isRegistrationFullyExpired({ expiry, gracePeriod: null }, 1001n)).toBe(true);
+    });
+  });
+
+  describe("isRegistrationInGracePeriod", () => {
+    it.each([
+      { now: 999n, expected: false, description: "before expiry" },
+      { now: 1000n, expected: true, description: "at expiry" },
+      { now: 1050n, expected: true, description: "during grace period" },
+      { now: 1100n, expected: false, description: "at expiry + grace period" },
+      { now: 1101n, expected: false, description: "after expiry + grace period" },
+    ])("returns $expected when $description", ({ now, expected }) => {
+      expect(isRegistrationInGracePeriod({ expiry, gracePeriod }, now)).toBe(expected);
+    });
+
+    it("returns false when expiry is null", () => {
+      expect(isRegistrationInGracePeriod({ expiry: null, gracePeriod }, 1050n)).toBe(false);
+    });
+
+    it("returns false when grace period is null", () => {
+      expect(isRegistrationInGracePeriod({ expiry, gracePeriod: null }, 1050n)).toBe(false);
+    });
+  });
+});
diff --git a/packages/ensnode-sdk/src/registrars/registration-expiration.ts b/packages/ensnode-sdk/src/registrars/registration-expiration.ts
index b81e7d696e..27a92c778a 100644
--- a/packages/ensnode-sdk/src/registrars/registration-expiration.ts
+++ b/packages/ensnode-sdk/src/registrars/registration-expiration.ts
@@ -23,8 +23,8 @@ export function isRegistrationFullyExpired(info: RegistrationExpiryInfo, now: bi
   // no expiry, never expired
   if (info.expiry == null) return false;
 
-  // otherwise it is expired if now >= expiry + grace
-  return now >= info.expiry + (info.gracePeriod ?? 0n);
+  // otherwise it is expired if now > expiry + grace
+  return now > info.expiry + (info.gracePeriod ?? 0n);
 }
 
 /**