diff --git a/source/migration.java b/source/migration.java
index bc181628f..b2cfb94b9 100644
--- a/source/migration.java
+++ b/source/migration.java
@@ -58,6 +58,12 @@ public class migration {
         migrateSwitchConfigSettings(sb);
         migrateWorkFiles(sb);
     }
+    public static void migrate(plasmaSwitchboard sb, int fromRev, int toRev){
+    	if(fromRev < toRev){
+    		serverLog.logInfo("MIGRATION", "Migrating from "+String.valueOf(fromRev)+ " to "+String.valueOf(toRev));
+    		migrate(sb);
+    	}
+    }
 
     public static void migrateWorkFiles(plasmaSwitchboard sb){
         File file=new File(sb.getRootPath(), "DATA/SETTINGS/wiki.db");
diff --git a/source/yacy.java b/source/yacy.java
index bea57e5c2..38c02dc81 100644
--- a/source/yacy.java
+++ b/source/yacy.java
@@ -184,6 +184,8 @@ public final class yacy {
     private static void startup(String homePath, long startupMemFree, long startupMemTotal) {
         long startup = System.currentTimeMillis();
         String restart = "false";
+        int oldRev=0;
+        int newRev=0;
         
         try {
             // start up
@@ -267,7 +269,8 @@ public final class yacy {
             } catch (Exception e) {
                 serverLog.logWarning("STARTUP", buildPropFile.toString() + " not found in settings path");
             }
-
+            
+            oldRev=Integer.parseInt(sb.getConfig("svnRevision", "0"));
             try {
                 if (buildProp.containsKey("releaseNr")) {
                     // this normally looks like this: $Revision$
@@ -283,6 +286,7 @@ public final class yacy {
                         sb.setConfig("svnRevision", svrReleaseNr);
                     }
                 }
+                newRev=Integer.parseInt(sb.getConfig("svnRevision", "0"));
             } catch (Exception e) {
                 System.err.println("Unable to determine the currently used SVN revision number.");
             }
@@ -353,7 +357,7 @@ public final class yacy {
             serverFileUtils.copy(new File(htRootPath, "htdocsdefault/dir.html"), new File(shareDefaultPath, "dir.html"));
             //} catch (IOException e) {}
 
-            migration.migrate(sb);
+            migration.migrate(sb, oldRev, newRev);
             
             // start main threads
             try {
diff --git a/yacy.init b/yacy.init
index 9b488d9d9..6aef05c16 100644
--- a/yacy.init
+++ b/yacy.init
@@ -697,3 +697,5 @@ httpc.nameCacheNoCachingPatterns = .*.dyndns.org, .*.dynalias.org
 #externalRedirectors
 #squid Redirector compatible
 externalRedirector=
+
+svnRevision=0