diff --git a/io/cmd.go b/io/cmd.go
index fbb373f..65cf5c8 100644
--- a/io/cmd.go
+++ b/io/cmd.go
@@ -89,6 +89,7 @@ func RunCmdWithOutputParser(config CmdConfig, prompt bool, regExpStruct ...*CmdO
 		return
 	}
 	errChan := make(chan error)
+	stdoutBuilder := strings.Builder{}
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
@@ -97,9 +98,11 @@ func RunCmdWithOutputParser(config CmdConfig, prompt bool, regExpStruct ...*CmdO
 			if prompt {
 				fmt.Fprintf(os.Stderr, line+"\n")
 			}
-			stdOut += line + "\n"
+			stdoutBuilder.WriteString(line)
+			stdoutBuilder.WriteRune('\n')
 		}
 	}()
+	stderrBuilder := strings.Builder{}
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
@@ -108,7 +111,8 @@ func RunCmdWithOutputParser(config CmdConfig, prompt bool, regExpStruct ...*CmdO
 			if prompt {
 				fmt.Fprintf(os.Stderr, line+"\n")
 			}
-			errorOut += line + "\n"
+			stderrBuilder.WriteString(line)
+			stderrBuilder.WriteRune('\n')
 			if hasError {
 				break
 			}
@@ -120,12 +124,11 @@ func RunCmdWithOutputParser(config CmdConfig, prompt bool, regExpStruct ...*CmdO
 		close(errChan)
 	}()
 
-	for channelErr := range errChan {
-		err = errors.Join(err, channelErr)
-	}
-	if err != nil {
+	for err = range errChan {
 		return
 	}
+	stdOut = stdoutBuilder.String()
+	errorOut = stderrBuilder.String()
 
 	err = cmd.Wait()
 	if err != nil {
diff --git a/io/cmd_test.go b/io/cmd_test.go
index 960c946..13cf5d0 100644
--- a/io/cmd_test.go
+++ b/io/cmd_test.go
@@ -12,24 +12,24 @@ var matchAllRegexp = regexp.MustCompile(".*")
 var errParsing = errors.New("parsing error")
 
 func TestRunCmdWithOutputParser(t *testing.T) {
-	config := NewCommand("git", "", []string{"status"})
+	config := NewCommand("go", "", []string{"version"})
 	stdout, stderr, exitOk, err := RunCmdWithOutputParser(config, false, &CmdOutputPattern{
 		RegExp:   matchAllRegexp,
 		ExecFunc: func(pattern *CmdOutputPattern) (string, error) { return pattern.Line, nil },
 	})
 	assert.NoError(t, err)
 	assert.True(t, exitOk)
-	assert.Contains(t, stdout, "On branch")
+	assert.Contains(t, stdout, "go version")
 	assert.Empty(t, stderr)
 }
 
 func TestRunCmdWithOutputParserError(t *testing.T) {
-	config := NewCommand("git", "", []string{"status"})
+	config := NewCommand("go", "", []string{"version"})
 	_, _, exitOk, err := RunCmdWithOutputParser(config, false, &CmdOutputPattern{
 		RegExp:   matchAllRegexp,
 		ExecFunc: func(pattern *CmdOutputPattern) (string, error) { return pattern.Line, errParsing },
 	})
-	assert.ErrorContains(t, err, "parsing error\nparsing error")
+	assert.ErrorContains(t, err, "parsing error")
 	assert.False(t, exitOk)
 }