diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.spec.ts b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.spec.ts
index 1fef554da..8b8c72843 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.spec.ts
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.spec.ts
@@ -126,4 +126,21 @@ describe('createSourceExpiryClock', () => {
         TestBed.tick();
         expect(jest.getTimerCount()).toBe(1);
     });
+
+    it('reads the clock at once when the sources rail is re-enabled', () => {
+        active.set(false);
+        TestBed.tick();
+        // Past the expiry while the rail is off: no boundary is left to wait
+        // for, so only the re-enable can refresh the cached badge.
+        facts.set(new Map([['xtream', expiringIn(60_000)]]));
+        TestBed.tick();
+        jest.advanceTimersByTime(3 * 60_000);
+        const before = clock();
+
+        active.set(true);
+        TestBed.tick();
+
+        expect(clock()).toBe(Date.now());
+        expect(clock()).toBeGreaterThan(before);
+    });
 });
diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.ts b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.ts
index 5a0c3a19d..b552e2393 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.ts
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-source-expiry-clock.ts
@@ -1,4 +1,11 @@
-import { DestroyRef, effect, inject, signal, type Signal } from '@angular/core';
+import {
+    DestroyRef,
+    effect,
+    inject,
+    signal,
+    untracked,
+    type Signal,
+} from '@angular/core';
 import { DOCUMENT } from '@angular/common';
 import {
     nextSourceExpiryChangeMs,
@@ -54,6 +61,16 @@ export function createSourceExpiryClock(
         onCleanup(() => clearTimeout(timer));
     });
 
+    // Re-enabling the rail must not show a badge cached while it was off: a
+    // boundary may have passed (an expired source has no next boundary to
+    // wait for), so read the clock at once, as becoming visible does.
+    let wasActive = untracked(active);
+    effect(() => {
+        const isActive = active();
+        if (isActive && !wasActive) untracked(() => now.set(Date.now()));
+        wasActive = isActive;
+    });
+
     const onVisibilityChange = () => {
         visible.set(!document.hidden);
         if (!document.hidden) now.set(Date.now());