1 files changed, 2 insertions, 1 deletions

diff --git a/src/Network/BitTorrent/Sessions.hs b/src/Network/BitTorrent/Sessions.hs
index f2035066..9713f438 100644
--- a/src/Network/BitTorrent/Sessions.hs
+++ b/src/Network/BitTorrent/Sessions.hs
@@ -297,7 +297,8 @@ defaultThreadCount = 1000
 enterSwarm :: SwarmSession -> IO ()
 enterSwarm SwarmSession {..} = do
   MSem.wait (activeThreads clientSession)
-  MSem.wait vacantPeers
+  MSem.wait vacantPeers `onException`
+    MSem.signal  (activeThreads clientSession)
 
 leaveSwarm :: SwarmSession -> IO ()
 leaveSwarm SwarmSession {..} = mask_ $ do