diff --git a/devslab-kit-identity-core/src/main/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenService.java b/devslab-kit-identity-core/src/main/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenService.java
index 9c4d2e8..a10c338 100644
--- a/devslab-kit-identity-core/src/main/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenService.java
+++ b/devslab-kit-identity-core/src/main/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenService.java
@@ -75,6 +75,12 @@ public Optional<CurrentUser> parse(String token) {
             Claims claims = Jwts.parser()
                     .verifyWith(signingKey)
                     .requireIssuer(issuer)
+                    // Validate expiration/not-before against the SAME injected clock
+                    // that issue() uses. JJWT's parser otherwise defaults to the real
+                    // system clock, which (a) makes the injected Clock untestable and
+                    // (b) is asymmetric with issue(). io.jsonwebtoken.Clock is a
+                    // {@code Date now()} functional interface, so adapt java.time.Clock.
+                    .clock(() -> Date.from(Instant.now(clock)))
                     .build()
                     .parseSignedClaims(token)
                     .getPayload();
diff --git a/devslab-kit-identity-core/src/test/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenServiceTest.java b/devslab-kit-identity-core/src/test/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenServiceTest.java
index 9fdc3d1..2978383 100644
--- a/devslab-kit-identity-core/src/test/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenServiceTest.java
+++ b/devslab-kit-identity-core/src/test/java/kr/devslab/kit/identity/core/service/JjwtAuthTokenServiceTest.java
@@ -55,4 +55,41 @@ void roundTripsMustChangePasswordFalse() {
 
         assertThat(parsed.mustChangePassword()).isFalse();
     }
+
+    /**
+     * Regression lock for the parser-clock bug: {@code parse()} must validate
+     * expiry against the <em>injected</em> clock, not the real system clock.
+     *
+     * <p>The clock is fixed far in the past, so the token's 8h window closed
+     * years ago in wall-clock terms. If {@code parse()} (re)introduces the
+     * default system clock, it sees the token as long expired and returns
+     * empty — and this assertion fails. It passes only while the injected clock
+     * governs expiry. Deterministic regardless of when CI runs.
+     */
+    @Test
+    void parseHonorsInjectedClock_acceptsTokenThatRealClockWouldReject() {
+        Clock past = Clock.fixed(Instant.parse("2020-01-01T00:00:00Z"), ZoneOffset.UTC);
+        JjwtAuthTokenService pastService =
+                new JjwtAuthTokenService(SECRET, Duration.ofHours(8), "devslab-kit-test", past);
+
+        AuthToken token = pastService.issue(user(false));
+
+        assertThat(pastService.parse(token.value())).isPresent();
+    }
+
+    /** And the symmetric case: a token past its TTL per the injected clock is rejected. */
+    @Test
+    void parseRejectsTokenExpiredPerInjectedClock() {
+        Clock t0 = Clock.fixed(Instant.parse("2026-05-31T00:00:00Z"), ZoneOffset.UTC);
+        JjwtAuthTokenService issuerService =
+                new JjwtAuthTokenService(SECRET, Duration.ofHours(1), "devslab-kit-test", t0);
+        AuthToken token = issuerService.issue(user(false));
+
+        // A reader whose clock sits 2h later — past the 1h TTL — must reject it.
+        Clock later = Clock.fixed(Instant.parse("2026-05-31T02:00:00Z"), ZoneOffset.UTC);
+        JjwtAuthTokenService readerService =
+                new JjwtAuthTokenService(SECRET, Duration.ofHours(1), "devslab-kit-test", later);
+
+        assertThat(readerService.parse(token.value())).isEmpty();
+    }
 }