diff --git a/bridged/src/main/java/dev/ltms/bridged/session/SessionReaper.java b/bridged/src/main/java/dev/ltms/bridged/session/SessionReaper.java
index 8f8b643..5d66713 100644
--- a/bridged/src/main/java/dev/ltms/bridged/session/SessionReaper.java
+++ b/bridged/src/main/java/dev/ltms/bridged/session/SessionReaper.java
@@ -27,7 +27,16 @@ public final class SessionReaper {
     private final long intervalMillis;
     private volatile boolean running;
     private Thread thread;
-    private volatile long lastWipSweepNanos = Long.MIN_VALUE;
+    /**
+     * When the retention sweep last ran, and whether it ever has. The flag is not a convenience:
+     * a "never yet" sentinel value cannot be compared by subtraction. {@code Long.MIN_VALUE} was
+     * the obvious choice and it silently overflows — {@code System.nanoTime()} is positive on this
+     * platform, so {@code now - Long.MIN_VALUE} wraps to a large negative number, the interval gate
+     * reads it as "swept moments ago", and it returns before ever assigning the field. The sweep
+     * then never runs at all, for the life of the process, with nothing in the log to say so.
+     */
+    private volatile boolean sweptOnce;
+    private volatile long lastWipSweepNanos;
 
     /** Construct a reaper with the default 5-second polling interval. */
     public SessionReaper(SessionManager sessions, long idleTtlSeconds) {
@@ -68,7 +77,11 @@ public final class SessionReaper {
      */
     private void maybeSweepWipRefs() {
         long now = System.nanoTime();
-        if (now - lastWipSweepNanos < WIP_SWEEP_INTERVAL_NANOS) {
+        // The first pass always sweeps: a restart is a fine moment to sweep, the 24h age floor
+        // makes it safe, and it means the feature is observable right after a redeploy instead of
+        // six hours later. Only after that does the interval gate apply, and by then both operands
+        // come from nanoTime, so the subtraction is well-defined.
+        if (sweptOnce && now - lastWipSweepNanos < WIP_SWEEP_INTERVAL_NANOS) {
             return;
         }
         try {
@@ -80,7 +93,10 @@ public final class SessionReaper {
         } catch (RuntimeException e) {
             log.warn("refs/wip retention sweep failed; continuing", e);
         }
+        // Set even when the sweep threw, so a broken repo is retried on the slow cadence rather
+        // than hammering git on every 5-second iteration.
         lastWipSweepNanos = now;
+        sweptOnce = true;
     }
 
     private void sleep() {
diff --git a/bridged/src/test/java/dev/ltms/bridged/session/SessionReaperTest.java b/bridged/src/test/java/dev/ltms/bridged/session/SessionReaperTest.java
index 027178f..5220055 100644
--- a/bridged/src/test/java/dev/ltms/bridged/session/SessionReaperTest.java
+++ b/bridged/src/test/java/dev/ltms/bridged/session/SessionReaperTest.java
@@ -11,10 +11,12 @@ import org.junit.jupiter.api.Test;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
 
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
@@ -90,6 +92,59 @@ class SessionReaperTest {
         return ticks.get() >= n;
     }
 
+    /**
+     * CB-586: the retention sweep must actually reach the seam when the loop runs.
+     *
+     * <p>The sweep's own tests call {@code SessionManager.sweepWipRefs} directly, which walks
+     * around the reaper's interval gate — and the gate is where it broke. {@code lastWipSweepNanos}
+     * started at {@code Long.MIN_VALUE}, so {@code now - lastWipSweepNanos} overflowed to a large
+     * negative number, the gate read that as "swept moments ago", and it returned <em>before</em>
+     * the assignment that would have fixed the field. The sweep never ran once, for the life of
+     * the process, and every direct-call test still passed.
+     *
+     * <p>So this asserts through the loop: spawn a worktree session (which is what tells the
+     * manager which repo holds {@code refs/wip/*}), start the reaper, and require a real prune call
+     * to arrive at the fake.
+     */
+    @Test
+    void theLoopActuallyRunsTheWipRetentionSweep() throws InterruptedException {
+        FakeHerdr herdr = new FakeHerdr();
+        FakeWorktrees worktrees = new FakeWorktrees().withRepoRoot("/repo").withPrefix("/wt");
+        SessionManager sessions = new SessionManager(launcher(herdr), worktrees);
+        // Without a worktree session the repo is unknown and the sweep is a legitimate no-op, so
+        // this step is what makes the assertion below meaningful rather than vacuous.
+        sessions.acquire("ltms-local", null, "/caller/proj", null, new WorktreeRequest("cb-586", null));
+        assertTrue(worktrees.pruneCalls().isEmpty(), "nothing has swept before the reaper starts");
+
+        SessionReaper reaper = new SessionReaper(sessions, IDLE_TTL_SECONDS, SHORT_INTERVAL_MILLIS);
+        reaper.start();
+        try {
+            long deadline = System.currentTimeMillis() + 3000;
+            while (worktrees.pruneCalls().isEmpty() && System.currentTimeMillis() < deadline) {
+                Thread.sleep(10);
+            }
+        } finally {
+            reaper.stop();
+        }
+
+        assertFalse(worktrees.pruneCalls().isEmpty(),
+                "the reaper loop must run the refs/wip retention sweep; it never reached the seam");
+        assertEquals("/repo", worktrees.pruneCalls().getFirst().repoRoot(),
+                "the sweep must target the repo the fleet's worktrees came from");
+        assertEquals(TimeUnit.HOURS.toMillis(24), worktrees.pruneCalls().getFirst().minAgeMillis(),
+                "the 24h age floor is the safety rule and must reach the seam intact");
+    }
+
+    /** As {@link #launcher()}, on a caller-supplied herdr so the test can inspect it. */
+    private static ClaudeCodeLauncher launcher(FakeHerdr herdr) {
+        BridgedConfig.Profile cfg = new BridgedConfig.Profile(
+                "ltms-local", "http://gx00.gw:8000", "coder", null, "BRIDGED_WORKER_TOKEN",
+                List.of("ccs", "ltms-local"), "tab", "bridged-workers",
+                "worker: {profile} #{n}", null, null, null);
+        return new ClaudeCodeLauncher(new AgentControl(herdr), new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), Map.of(cfg.profile(), cfg), cfg.profile(), _ -> null);
+    }
+
     @Test
     void stopIsIdempotentAndSafeBeforeStart() {
         SessionReaper reaper = reaper();