diff --git a/history.txt b/history.txt
index 9f89b5b8e1..1d818997e5 100644
--- a/history.txt
+++ b/history.txt
@@ -1,3 +1,6 @@
+2012-10-21 zzz
+ * Watchdog: Don't dump threads too often (ticket #519)
+
 2012-10-20 zzz
  * Transport: Back out CoDel for SSU PeerState and NTCP
 
diff --git a/router/java/src/net/i2p/router/RouterVersion.java b/router/java/src/net/i2p/router/RouterVersion.java
index 098e16d499..14408f1ed4 100644
--- a/router/java/src/net/i2p/router/RouterVersion.java
+++ b/router/java/src/net/i2p/router/RouterVersion.java
@@ -18,7 +18,7 @@ public class RouterVersion {
     /** deprecated */
     public final static String ID = "Monotone";
     public final static String VERSION = CoreVersion.VERSION;
-    public final static long BUILD = 17;
+    public final static long BUILD = 18;
 
     /** for example "-test" */
     public final static String EXTRA = "-rc";
diff --git a/router/java/src/net/i2p/router/tasks/RouterWatchdog.java b/router/java/src/net/i2p/router/tasks/RouterWatchdog.java
index 233c3bd7a0..b37087f1c5 100644
--- a/router/java/src/net/i2p/router/tasks/RouterWatchdog.java
+++ b/router/java/src/net/i2p/router/tasks/RouterWatchdog.java
@@ -23,8 +23,10 @@ public class RouterWatchdog implements Runnable {
     private final RouterContext _context;
     private int _consecutiveErrors;
     private volatile boolean _isRunning;
+    private long _lastDump;
     
     private static final long MAX_JOB_RUN_LAG = 60*1000;
+    private static final long MIN_DUMP_INTERVAL= 6*60*60*1000;
     
     public RouterWatchdog(RouterContext ctx) {
         _context = ctx;
@@ -69,7 +71,7 @@ public class RouterWatchdog implements Runnable {
 
         // Client manager starts complaining after 10 minutes, and we run every minute,
         // so this will restart 30 minutes after we lose a lease, if the wrapper is present.
-        if (_consecutiveErrors >= 20 && System.getProperty("wrapper.version") != null)
+        if (_consecutiveErrors >= 20 && SystemVersion.hasWrapper())
             return true;
         return false;
     }
@@ -113,7 +115,11 @@ public class RouterWatchdog implements Runnable {
                 // This works on linux...
                 // It won't on windows, and we can't call i2prouter.bat either, it does something
                 // completely different...
-                ThreadDump.dump(_context, 10);
+                long now = _context.clock().now();
+                if (now - _lastDump > MIN_DUMP_INTERVAL) {
+                    _lastDump = now;
+                    ThreadDump.dump(_context, 10);
+                }
             }
         }
     }