diff --git a/implementations/main.cpp b/implementations/main.cpp
index be86315..607e764 100644
--- a/implementations/main.cpp
+++ b/implementations/main.cpp
@@ -1589,6 +1589,38 @@ struct Claim {
 };
 Claim g_claim;
 GDBusMethodInvocation* g_pendingClaim = nullptr;
+guint g_claimWatch = 0;
+
+void DropClaim(const char* why) {
+    if (g_claimWatch) {
+        g_dbus_connection_signal_unsubscribe(g_conn, g_claimWatch);
+        g_claimWatch = 0;
+    }
+    if (g_claim.op != Op::None && g_worker) g_worker->CancelOp();
+    if (g_claim.held)
+        std::println("claim by {} for {} dropped: {}", g_claim.sender, g_claim.user, why);
+    g_claim = {};
+}
+
+// A claim is held by a bus connection. If that connection goes away -- the
+// client crashed, was killed, or simply never called Release -- the claim
+// must go with it, or the device is wedged for everyone until the daemon
+// restarts. fprintd watches the claimant's name for exactly this reason. Seen
+// the hard way: a Claim from one busctl invocation, which exits immediately,
+// left the device permanently "AlreadyInUse".
+void WatchClaimant(const std::string& sender) {
+    g_claimWatch = g_dbus_connection_signal_subscribe(
+        g_conn, "org.freedesktop.DBus", "org.freedesktop.DBus", "NameOwnerChanged",
+        "/org/freedesktop/DBus", sender.c_str(), G_DBUS_SIGNAL_FLAGS_NONE,
+        [](GDBusConnection*, const gchar*, const gchar*, const gchar*, const gchar*,
+           GVariant* params, gpointer) {
+            const gchar* name = nullptr; const gchar* oldOwner = nullptr; const gchar* newOwner = nullptr;
+            g_variant_get(params, "(&s&s&s)", &name, &oldOwner, &newOwner);
+            if (g_claim.held && name && g_claim.sender == name && newOwner && *newOwner == '\0')
+                DropClaim("client left the bus");
+        },
+        nullptr, nullptr);
+}
 
 std::string MapPath(std::uint32_t uid) {
     return fingerprintd::store::PathForUid(g_stateDir, uid);
@@ -1685,7 +1717,7 @@ void PostEvent(std::unique_ptr<Event> ev) {
                                  g_claim.sender, g_claim.user, g_claim.uid, ev->templates);
                     g_dbus_method_invocation_return_value(ev->invocation, nullptr);
                 } else {
-                    g_claim = {};
+                    DropClaim("group selection failed");
                     ReturnError(ev->invocation, "Internal", "could not select the user's group");
                 }
                 g_pendingClaim = nullptr;
@@ -1763,6 +1795,7 @@ void HandleDevice(GDBusMethodInvocation* inv, std::string_view method, GVariant*
         g_claim.uid = who->second;
         g_claim.fingers = LoadMap(g_claim.uid);
         g_pendingClaim = inv;
+        WatchClaimant(g_claim.sender);
         g_worker->Post(Job{ .kind = Job::Kind::Claim, .uid = g_claim.uid, .invocation = inv });
         return;
     }
@@ -1771,8 +1804,7 @@ void HandleDevice(GDBusMethodInvocation* inv, std::string_view method, GVariant*
             ReturnError(inv, "ClaimDevice", "device is not claimed by you");
             return;
         }
-        if (g_claim.op != Op::None) g_worker->CancelOp();
-        g_claim = {};
+        DropClaim("released");
         g_dbus_method_invocation_return_value(inv, nullptr);
         return;
     }