diff --git a/config_example.json b/config_example.json
index 4763ad2..944b8f8 100644
--- a/config_example.json
+++ b/config_example.json
@@ -57,6 +57,10 @@
             "invalidPercent": 25,
             "checkThreshold": 30
         },
+        "fixedDiff": {
+            "enabled": true,
+            "addressSeparator": "."
+        },
         "slushMining": {
             "enabled": false,
             "weight": 300,
diff --git a/lib/pool.js b/lib/pool.js
index 2b0ae2f..2976f8e 100644
--- a/lib/pool.js
+++ b/lib/pool.js
@@ -56,7 +56,9 @@ setInterval(function(){
     var now = Date.now() / 1000 | 0;
     for (var minerId in connectedMiners){
         var miner = connectedMiners[minerId];
-        miner.retarget(now);
+        if(!miner.noRetarget) {
+            miner.retarget(now);
+        }
     }
 }, config.poolServer.varDiff.retargetTime * 1000);
 
@@ -200,12 +202,13 @@ var VarDiff = (function(){
     };
 })();
 
-function Miner(id, login, pass, ip, startingDiff, pushMessage){
+function Miner(id, login, pass, ip, startingDiff, noRetarget, pushMessage){
     this.id = id;
     this.login = login;
     this.pass = pass;
     this.ip = ip;
     this.pushMessage = pushMessage;
+    this.noRetarget = noRetarget;
     this.heartbeat();
     this.difficulty = startingDiff;
     this.validJobs = [];
@@ -358,7 +361,7 @@ function recordShareData(miner, job, shareDiff, blockCandidate, hashHex, shareTy
     var dateNowSeconds = dateNow / 1000 | 0;
 
     //Weighting older shares lower than newer ones to prevent pool hopping
-    if (config.poolServer.slushMining.enabled) {                
+    if (config.poolServer.slushMining.enabled) {
         if (lastChecked + config.poolServer.slushMining.lastBlockCheckRate <= dateNowSeconds || lastChecked == 0) {
             redisClient.hget(config.coin + ':stats', 'lastBlockFound', function(error, result) {
                 if (error) {
@@ -369,7 +372,7 @@ function recordShareData(miner, job, shareDiff, blockCandidate, hashHex, shareTy
                 lastChecked = dateNowSeconds;
             });
         }
-        
+
         job.score = job.difficulty * Math.pow(Math.E, ((dateNowSeconds - scoreTime) / config.poolServer.slushMining.weight)); //Score Calculation
         log('info', logSystem, 'Submitted score ' + job.score + ' with difficulty ' + job.difficulty + ' and the time ' + scoreTime);
     }
@@ -495,23 +498,42 @@ function handleMinerMethod(method, params, ip, portData, sendReply, pushMessage)
 
     switch(method){
         case 'login':
-            if (!params.login){
+            var login = params.login;
+            if (!login){
                 sendReply('missing login');
                 return;
             }
-            if (!utils.isValidAddress(params.login, config.poolServer.poolAddress[0])){
+            if (!utils.isValidAddress(login, config.poolServer.poolAddress[0])){
                 sendReply('invalid address used for login');
                 return;
             }
+
+            var difficulty = portData.difficulty;
+            var noRetarget = portData.noRetarget;
+            if(config.poolServer.fixedDiff.enabled) {
+                var fixedDiffCharPos = login.indexOf(config.poolServer.fixedDiff.addressSeparator);
+                if(fixedDiffCharPos != -1) {
+                    noRetarget = true;
+                    difficulty = parseInt(login.substr(fixedDiffCharPos + 1)) || portData.difficulty;
+                    if(!difficulty || difficulty < config.poolServer.varDiff.minDiff) {
+                        difficulty = config.poolServer.varDiff.minDiff;
+                        noRetarget = portData.noRetarget;
+                    }
+
+                    login = login.substr(0, fixedDiffCharPos);
+                    log('info', logSystem, 'Miner difficulty fixed to %s',  [difficulty]);
+                }
+            }
+
             var minerId = utils.uid();
-            miner = new Miner(minerId, params.login, params.pass, ip, portData.difficulty, pushMessage);
+            miner = new Miner(minerId, login, params.pass, ip, difficulty, noRetarget, pushMessage);
             connectedMiners[minerId] = miner;
             sendReply(null, {
                 id: minerId,
                 job: miner.getJob(),
                 status: 'OK'
             });
-            log('info', logSystem, 'Miner connected %s@%s',  [params.login, miner.ip]);
+            log('info', logSystem, 'Miner connected %s@%s',  [login, miner.ip]);
             break;
         case 'getjob':
             if (!miner){