diff --git a/router/java/src/net/i2p/router/tunnel/TunnelGatewayPumper.java b/router/java/src/net/i2p/router/tunnel/TunnelGatewayPumper.java
index 205086472..05db0b0ce 100644
--- a/router/java/src/net/i2p/router/tunnel/TunnelGatewayPumper.java
+++ b/router/java/src/net/i2p/router/tunnel/TunnelGatewayPumper.java
@@ -2,6 +2,8 @@ package net.i2p.router.tunnel;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
 
 import net.i2p.router.RouterContext;
 import net.i2p.util.I2PThread;
@@ -12,27 +14,36 @@ import net.i2p.util.I2PThread;
  */
 public class TunnelGatewayPumper implements Runnable {
     private RouterContext _context;
-    private final List<PumpedTunnelGateway> _wantsPumping;
+    private final BlockingQueue<PumpedTunnelGateway> _wantsPumping;
     private boolean _stop;
+    private static final int PUMPERS = 4;
     
     /** Creates a new instance of TunnelGatewayPumper */
     public TunnelGatewayPumper(RouterContext ctx) {
         _context = ctx;
-        _wantsPumping = new ArrayList(64);
+        _wantsPumping = new LinkedBlockingQueue();
         _stop = false;
-        for (int i = 0; i < 4; i++)
-            new I2PThread(this, "GW pumper " + i, true).start();
+        for (int i = 0; i < PUMPERS; i++)
+            new I2PThread(this, "Tunnel GW pumper " + i + '/' + PUMPERS, true).start();
     }
+
     public void stopPumping() {
         _stop=true;
-        synchronized (_wantsPumping) { _wantsPumping.notifyAll(); }
+        _wantsPumping.clear();
+        PumpedTunnelGateway poison = new PoisonPTG(_context);
+        for (int i = 0; i < PUMPERS; i++)
+            _wantsPumping.offer(poison);
+        for (int i = 1; i <= 5 && !_wantsPumping.isEmpty(); i++) {
+            try {
+                Thread.sleep(i * 50);
+            } catch (InterruptedException ie) {}
+        }
+        _wantsPumping.clear();
     }
     
     public void wantsPumping(PumpedTunnelGateway gw) {
-        synchronized (_wantsPumping) {
-            _wantsPumping.add(gw);
-            _wantsPumping.notify();
-        }
+        if (!_stop)
+            _wantsPumping.offer(gw);
     }
     
     public void run() {
@@ -40,17 +51,25 @@ public class TunnelGatewayPumper implements Runnable {
         List<TunnelGateway.Pending> queueBuf = new ArrayList(32);
         while (!_stop) {
             try {
-                synchronized (_wantsPumping) {
-                    if (_wantsPumping.size() > 0)
-                        gw = _wantsPumping.remove(0);
-                    else
-                        _wantsPumping.wait();
-                }
+                gw = _wantsPumping.take();
             } catch (InterruptedException ie) {}
             if (gw != null) {
+                if (gw.getMessagesSent() == POISON_PTG)
+                    break;
                 gw.pump(queueBuf);
                 gw = null;
             }
         }
     }
+
+    private static final int POISON_PTG = -99999;
+
+    private static class PoisonPTG extends PumpedTunnelGateway {
+        public PoisonPTG(RouterContext ctx) {
+            super(ctx, null, null, null, null);
+        }
+
+        @Override
+        public int getMessagesSent() { return POISON_PTG; }
+    }
 }