diff --git a/src/models/StratumV1Client.ts b/src/models/StratumV1Client.ts
index ebe8dff..68b4b9d 100644
--- a/src/models/StratumV1Client.ts
+++ b/src/models/StratumV1Client.ts
@@ -111,7 +111,7 @@ export class StratumV1Client extends EasyUnsubscribe {
                     const err = new StratumErrorMessage(
                         subscriptionMessage.id,
                         eStratumErrorCode.OtherUnknown,
-                        'Subscription error',
+                        'Subscription validation error',
                         errors).response();
                     console.error(err);
                     await this.promiseSocket.write(err);
@@ -141,7 +141,7 @@ export class StratumV1Client extends EasyUnsubscribe {
                     const err = new StratumErrorMessage(
                         configurationMessage.id,
                         eStratumErrorCode.OtherUnknown,
-                        'Configuration error',
+                        'Configuration validation error',
                         errors).response();
                     console.error(err);
                     await this.promiseSocket.write(err);
@@ -171,7 +171,7 @@ export class StratumV1Client extends EasyUnsubscribe {
                     const err = new StratumErrorMessage(
                         authorizationMessage.id,
                         eStratumErrorCode.OtherUnknown,
-                        'Authorization error',
+                        'Authorization validation error',
                         errors).response();
                     console.error(err);
                     await this.promiseSocket.write(err);
@@ -206,7 +206,7 @@ export class StratumV1Client extends EasyUnsubscribe {
                     const err = new StratumErrorMessage(
                         suggestDifficultyMessage.id,
                         eStratumErrorCode.OtherUnknown,
-                        'Suggest difficulty error',
+                        'Suggest difficulty validation error',
                         errors).response();
                     console.error(err);
                     await this.promiseSocket.write(err);
@@ -237,7 +237,7 @@ export class StratumV1Client extends EasyUnsubscribe {
                     const err = new StratumErrorMessage(
                         miningSubmitMessage.id,
                         eStratumErrorCode.OtherUnknown,
-                        'Suggest difficulty error',
+                        'Mining Submit validation error',
                         errors).response();
                     console.error(err);
                     await this.promiseSocket.write(err);
diff --git a/src/models/stratum-messages/MiningSubmitMessage.ts b/src/models/stratum-messages/MiningSubmitMessage.ts
index 4e254da..127689c 100644
--- a/src/models/stratum-messages/MiningSubmitMessage.ts
+++ b/src/models/stratum-messages/MiningSubmitMessage.ts
@@ -45,7 +45,7 @@ export class MiningSubmitMessage extends StratumBaseMessage {
     @Expose()
     @IsString()
     @Transform(({ value, key, obj, type }) => {
-        return obj.params[5] == null ? 0 : obj.params[5];
+        return obj.params[5] == null ? '0' : obj.params[5];
     })
     public versionMask?: string | null;