diff --git a/crates/chanora_audio/src/ptt_backends/linux.rs b/crates/chanora_audio/src/ptt_backends/linux.rs
index 68146e5..a0ac894 100644
--- a/crates/chanora_audio/src/ptt_backends/linux.rs
+++ b/crates/chanora_audio/src/ptt_backends/linux.rs
@@ -231,16 +231,33 @@ enum WorkerCmd {
 impl LinuxGnomeWaylandBackend {
     /// Synchronous probe via the blocking proxy. Cheap; runs once
     /// at `try_select` time before we commit to the live flow.
+    ///
+    /// `zbus::blocking` internally spins up its own current-thread
+    /// tokio runtime to drive the async D-Bus client. If we called
+    /// it directly here we would panic with "Cannot start a runtime
+    /// from within a runtime" because `try_select()` is invoked
+    /// from `PttController::new`, which is called from the audio
+    /// engine start path, which runs on the bridge's tokio
+    /// multi-thread runtime. We therefore push the blocking probe
+    /// onto a fresh OS thread (no ambient runtime), join it
+    /// synchronously, and propagate the result. The probe is in
+    /// the millisecond range so the join cost is negligible.
     fn probe() -> Result<Self, PttBackendError> {
-        let conn = BlockingConnection::session()
-            .map_err(|e| PttBackendError::Init(format!("session bus: {e}")))?;
-        let version = {
-            let proxy = BlockingGlobalShortcutsProxy::new(&conn)
-                .map_err(|e| PttBackendError::Init(format!("proxy: {e}")))?;
-            proxy
-                .version()
-                .map_err(|e| PttBackendError::Init(format!("portal version: {e}")))?
-        };
+        let join_result = std::thread::Builder::new()
+            .name("chanora-ptt-portal-probe".to_string())
+            .spawn(|| -> Result<u32, String> {
+                let conn = BlockingConnection::session()
+                    .map_err(|e| format!("session bus: {e}"))?;
+                let proxy = BlockingGlobalShortcutsProxy::new(&conn)
+                    .map_err(|e| format!("proxy: {e}"))?;
+                proxy
+                    .version()
+                    .map_err(|e| format!("portal version: {e}"))
+            })
+            .map_err(|e| PttBackendError::Init(format!("probe thread spawn: {e}")))?
+            .join()
+            .map_err(|_| PttBackendError::Init("probe thread panicked".to_string()))?;
+        let version = join_result.map_err(PttBackendError::Init)?;
         info!(
             target: "chanora_audio",
             portal_version = version,