diff --git a/pkg/mining/profile_manager.go b/pkg/mining/profile_manager.go
index ec1e926..08214aa 100644
--- a/pkg/mining/profile_manager.go
+++ b/pkg/mining/profile_manager.go
@@ -2,7 +2,6 @@ package mining
 
 import (
 	"encoding/json"
-	"fmt"
 	"os"
 	"path/filepath"
 	"sync"
@@ -26,7 +25,7 @@ type ProfileManager struct {
 func NewProfileManager() (*ProfileManager, error) {
 	configPath, err := xdg.ConfigFile(filepath.Join("lethean-desktop", profileConfigFileName))
 	if err != nil {
-		return nil, fmt.Errorf("could not resolve config path: %w", err)
+		return nil, ErrInternal("could not resolve config path").WithCause(err)
 	}
 
 	profileManager := &ProfileManager{
@@ -37,7 +36,7 @@ func NewProfileManager() (*ProfileManager, error) {
 	if err := profileManager.loadProfiles(); err != nil {
 		// If the file doesn't exist, that's fine, but any other error is a problem.
 		if !os.IsNotExist(err) {
-			return nil, fmt.Errorf("could not load profiles: %w", err)
+			return nil, ErrInternal("could not load profiles").WithCause(err)
 		}
 	}
 
@@ -129,7 +128,7 @@ func (profileManager *ProfileManager) UpdateProfile(profile *MiningProfile) erro
 
 	oldProfile, exists := profileManager.profiles[profile.ID]
 	if !exists {
-		return fmt.Errorf("profile with ID %s not found", profile.ID)
+		return ErrProfileNotFound(profile.ID)
 	}
 
 	// Update in-memory state
@@ -139,7 +138,7 @@ func (profileManager *ProfileManager) UpdateProfile(profile *MiningProfile) erro
 	if err := profileManager.saveProfiles(); err != nil {
 		// Restore old profile on save failure
 		profileManager.profiles[profile.ID] = oldProfile
-		return fmt.Errorf("failed to save profile: %w", err)
+		return ErrInternal("failed to save profile").WithCause(err)
 	}
 
 	return nil
@@ -152,7 +151,7 @@ func (profileManager *ProfileManager) DeleteProfile(id string) error {
 
 	profile, exists := profileManager.profiles[id]
 	if !exists {
-		return fmt.Errorf("profile with ID %s not found", id)
+		return ErrProfileNotFound(id)
 	}
 	delete(profileManager.profiles, id)
 
@@ -160,7 +159,7 @@ func (profileManager *ProfileManager) DeleteProfile(id string) error {
 	if err := profileManager.saveProfiles(); err != nil {
 		// Restore profile on save failure
 		profileManager.profiles[id] = profile
-		return fmt.Errorf("failed to delete profile: %w", err)
+		return ErrInternal("failed to delete profile").WithCause(err)
 	}
 
 	return nil