diff --git a/pkg/mining/miner.go b/pkg/mining/miner.go
index 70872a2..082143d 100644
--- a/pkg/mining/miner.go
+++ b/pkg/mining/miner.go
@@ -5,7 +5,6 @@ import (
 	"archive/zip"
 	"bytes"
 	"compress/gzip"
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -152,7 +151,7 @@ func (b *BaseMiner) Stop() error {
 
 	if !b.Running || b.cmd == nil {
 		b.mu.Unlock()
-		return errors.New("miner is not running")
+		return ErrMinerNotRunning(b.Name)
 	}
 
 	// Close stdin pipe if open
@@ -210,7 +209,7 @@ func (b *BaseMiner) WriteStdin(input string) error {
 	b.mu.RUnlock()
 
 	if !running || stdinPipe == nil {
-		return errors.New("miner is not running or stdin not available")
+		return ErrMinerNotRunning(b.Name)
 	}
 
 	// Append newline if not present
@@ -235,7 +234,7 @@ func (b *BaseMiner) WriteStdin(input string) error {
 	case err := <-done:
 		return err
 	case <-time.After(stdinWriteTimeout):
-		return errors.New("stdin write timeout: miner may be unresponsive")
+		return ErrTimeout("stdin write: miner may be unresponsive")
 	}
 }