diff --git a/src/models/StratumV1Client.ts b/src/models/StratumV1Client.ts
index 4189872..ec16daa 100644
--- a/src/models/StratumV1Client.ts
+++ b/src/models/StratumV1Client.ts
@@ -36,6 +36,7 @@ export class StratumV1Client {
     private clientAuthorization: AuthorizationMessage;
     private clientSuggestedDifficulty: SuggestDifficulty;
     private stratumSubscription: Subscription;
+    private backgroundWork: NodeJS.Timer;
 
     private statistics: StratumV1ClientStatistics;
     private stratumInitialized = false;
@@ -82,6 +83,7 @@ export class StratumV1Client {
 
     public destroy() {
         this.stratumSubscription.unsubscribe();
+        clearInterval(this.backgroundWork);
     }
 
     private getRandomHexString() {
@@ -275,6 +277,12 @@ export class StratumV1Client {
 
             this.stratumInitialized = true;
 
+            switch (this.clientSubscription.userAgent) {
+                case 'cpuminer': {
+                    this.sessionDifficulty = 0.1;
+                }
+            }
+
 
             if (this.clientSuggestedDifficulty == null) {
                 console.log(`Setting difficulty to ${this.sessionDifficulty}`)
@@ -297,14 +305,18 @@ export class StratumV1Client {
             ).subscribe(async (jobTemplate) => {
                 try {
                     await this.sendNewMiningJob(jobTemplate);
-                    await this.checkDifficulty();
-                    await this.watchdog();
+
                 } catch (e) {
                     this.promiseSocket.socket.emit('end', true);
                     console.error(e);
                 }
             });
 
+            this.backgroundWork = setInterval(async () => {
+                await this.checkDifficulty();
+                await this.watchdog();
+            }, 60 * 1000);
+
         }
     }
 
@@ -454,7 +466,7 @@ export class StratumV1Client {
             return false;
         }
 
-        await this.checkDifficulty();
+        //await this.checkDifficulty();
         return true;
 
     }
diff --git a/src/models/StratumV1ClientStatistics.ts b/src/models/StratumV1ClientStatistics.ts
index 60c3bc5..83012f4 100644
--- a/src/models/StratumV1ClientStatistics.ts
+++ b/src/models/StratumV1ClientStatistics.ts
@@ -52,13 +52,13 @@ export class StratumV1ClientStatistics {
     public getSuggestedDifficulty(clientDifficulty: number) {
 
         // miner hasn't submitted shares in one minute
-        if (this.submissionCache.length == 0 && (new Date().getTime() - this.submissionCacheStart.getTime()) / 1000 > 60) {
+        if (this.submissionCache.length == 0 || (new Date().getTime() - this.submissionCacheStart.getTime()) / 1000 > 60) {
             return this.nearestPowerOfTwo(clientDifficulty >> 1);
         }
 
-        if (this.submissionCache.length < CACHE_SIZE) {
-            return null;
-        }
+        // if (this.submissionCache.length < CACHE_SIZE) {
+        //     return null;
+        // }
 
         const sum = this.submissionCache.reduce((pre, cur) => {
             pre += cur.difficulty;
@@ -75,7 +75,6 @@ export class StratumV1ClientStatistics {
         }
 
         return null;
-
     }
 
     private nearestPowerOfTwo(val): number {