diff --git a/app/modules/prover/lib/blockProver.ts b/app/modules/prover/lib/blockProver.ts
index 5217aab5fea5f6f83598d99ddfafc9c0b35a3919..0e872ed3e9bb2711f66ab6e2fb3a7c9beaf36684 100644
--- a/app/modules/prover/lib/blockProver.ts
+++ b/app/modules/prover/lib/blockProver.ts
@@ -206,6 +206,7 @@ export class BlockProver {
   }
 
   async changePoWPrefix(prefix:any) {
+    this.conf.prefix = prefix
     const farm = await this.getWorker()
     return farm.changePoWPrefix(prefix)
   }
diff --git a/app/modules/prover/lib/constants.ts b/app/modules/prover/lib/constants.ts
index 0b10fbf483f47319caa3327aa9fe27c4402f2e3e..5de1c0e729ed016fc06f90b7abe06f7d0c4f97a2 100644
--- a/app/modules/prover/lib/constants.ts
+++ b/app/modules/prover/lib/constants.ts
@@ -7,6 +7,8 @@ export const Constants = {
   POW_MINIMAL_TO_SHOW: 2,
   DEFAULT_CPU: 0.6,
   DEFAULT_PEER_ID: 1,
+  MIN_PEER_ID: 1,
+  MAX_PEER_ID: 999999,
 
   NONCE_RANGE: 1000 * 1000 * 1000 * 100,
 
diff --git a/app/modules/prover/lib/prover.ts b/app/modules/prover/lib/prover.ts
index 182f5e3fec4ef7077efa1d13ace7c21c95ba7dbb..3bd85abdbd8a8f9d15fdaa75e1dd2c38cbeee219 100644
--- a/app/modules/prover/lib/prover.ts
+++ b/app/modules/prover/lib/prover.ts
@@ -17,9 +17,7 @@ export class Prover extends stream.Transform {
     if (obj) {
       if (obj.bcEvent && obj.bcEvent === OtherConstants.BC_EVENT.HEAD_CHANGED || obj.bcEvent === OtherConstants.BC_EVENT.SWITCHED) {
         this.permaProver.blockchainChanged(obj.block);
-      } /*else if (obj.nodeIndexInPeers !== undefined) {
-        this.permaProver.prover.changePoWPrefix((obj.nodeIndexInPeers + 1) * 10); // We multiply by 10 to give room to computers with < 100 cores
-      }*/ else if (obj.cpu !== undefined) {
+      } else if (obj.cpu !== undefined) {
         this.permaProver.prover.changeCPU(obj.cpu); // We multiply by 10 to give room to computers with < 100 cores
       }
     }
diff --git a/app/service/PeeringService.ts b/app/service/PeeringService.ts
index c056fe89f45c3e4071b233c32edc794273315314..2e93ff557e3b86f1f52cd5c3dec59636212f8892 100644
--- a/app/service/PeeringService.ts
+++ b/app/service/PeeringService.ts
@@ -161,16 +161,6 @@ export class PeeringService {
           const localEndpoints = await this.server.getEndpoints()
           const localNodeNotListed = !peerEntityOld.containsAllEndpoints(localEndpoints)
           const current = localNodeNotListed && (await this.dal.getCurrentBlockOrNull());
-          /*if (!localNodeNotListed) {
-            const indexOfThisNode = PeerDTO.indexOfFirst(localEndpoints, peerEntity.endpoints)
-            if (indexOfThisNode !== -1) {
-              this.server.push({
-                nodeIndexInPeers: indexOfThisNode
-              });
-            } else {
-              logger.warn('This node has his interface listed in the peer document, but its index cannot be found.');
-            }
-          }*/
           if (localNodeNotListed && (!current || current.number > blockNumber)) {
             // Document with pubkey of local peer, but doesn't contain local interface: we must add it
             this.generateSelfPeer(this.conf);
diff --git a/index.ts b/index.ts
index 08eaccdc996ed0823622101a88969b4f4e59a373..3c6b04bc5ad36d1aae2701a97854444164bb3c76 100644
--- a/index.ts
+++ b/index.ts
@@ -7,6 +7,7 @@ import {KeypairDependency} from "./app/modules/keypair/index"
 import {CrawlerDependency} from "./app/modules/crawler/index"
 import {BmaDependency} from "./app/modules/bma/index"
 import {WS2PDependency} from "./app/modules/ws2p/index"
+import {Constants} from "./app/modules/prover/lib/constants"
 
 const path = require('path');
 const _ = require('underscore');
@@ -468,7 +469,7 @@ function commandLineConf(program:any, conf:any = {}) {
   if (cli.currency)                         conf.currency = cli.currency;
   if (cli.server.port)                      conf.port = cli.server.port;
   if (cli.cpu)                              conf.cpu = Math.max(0.01, Math.min(1.0, cli.cpu));
-  if (cli.prefix)                           conf.prefix = Math.max(1, Math.min(9, cli.prefix));
+  if (cli.prefix)                           conf.prefix = Math.max(Constants.MIN_PEER_ID, Math.min(Constants.MAX_PEER_ID, cli.prefix));
   if (cli.logs.http)                        conf.httplogs = true;
   if (cli.logs.nohttp)                      conf.httplogs = false;
   if (cli.db.mport)                         conf.mport = cli.db.mport;
diff --git a/test/fast/prover/pow-3-prover.js b/test/fast/prover/pow-3-prover.js
index 9012c146fbadc84e11423e74d790fbbf2d8cb051..8704ad5d232179d3f633685509d38b3c6e593e0a 100644
--- a/test/fast/prover/pow-3-prover.js
+++ b/test/fast/prover/pow-3-prover.js
@@ -68,6 +68,19 @@ describe('PoW block prover', () => {
     });
   }));
 
+  it('should be able to use a prefix with 6 digits', () => co(function*(){
+    const block = {
+      number: 1,
+      issuer: 'HgTTJLAQ5sqfknMq7yLPZbehtuLSsKj9CxWN7k8QvYJd'
+    }
+    const params = yield prover.changePoWPrefix('123456')
+    params.should.deepEqual({ prefix: '123456' })
+    const forcedTime = 1;
+    const proof = yield prover.prove(block, 1, forcedTime)
+    proof.nonce.should.equal(123456000000000000)
+    String(proof.nonce).should.have.length(18)
+  }));
+
   it('should be able to stop a proof', () => co(function*(){
     const block = {
       number: 35,