diff --git a/backend/internal/service/oidc_service.go b/backend/internal/service/oidc_service.go
index f8db7d6d..e37bbe0b 100644
--- a/backend/internal/service/oidc_service.go
+++ b/backend/internal/service/oidc_service.go
@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"gorm.io/gorm/clause"
 	"log"
 	"mime/multipart"
 	"os"
@@ -94,24 +95,8 @@ func (s *OidcService) Authorize(ctx context.Context, input dto.AuthorizeOidcClie
 
 	// If the user has not authorized the client, create a new authorization in the database
 	if !hasAuthorizedClient {
-		userAuthorizedClient := model.UserAuthorizedOidcClient{
-			UserID:   userID,
-			ClientID: input.ClientID,
-			Scope:    input.Scope,
-		}
-
-		err = tx.
-			WithContext(ctx).
-			Create(&userAuthorizedClient).
-			Error
-		if errors.Is(err, gorm.ErrDuplicatedKey) {
-			// The client has already been authorized but with a different scope so we need to update the scope
-			if err := tx.
-				WithContext(ctx).
-				Model(&userAuthorizedClient).Update("scope", input.Scope).Error; err != nil {
-				return "", "", err
-			}
-		} else if err != nil {
+		err := s.createAuthorizedClientInternal(ctx, userID, input.ClientID, input.Scope, tx)
+		if err != nil {
 			return "", "", err
 		}
 	}
@@ -201,7 +186,7 @@ func (s *OidcService) createTokenFromDeviceCode(ctx context.Context, deviceCode,
 		tx.Rollback()
 	}()
 
-	_, err = s.VerifyClientCredentials(ctx, clientID, clientSecret, tx)
+	_, err = s.verifyClientCredentialsInternal(ctx, clientID, clientSecret, tx)
 	if err != nil {
 		return "", "", "", 0, err
 	}
@@ -269,7 +254,7 @@ func (s *OidcService) createTokenFromAuthorizationCode(ctx context.Context, code
 		tx.Rollback()
 	}()
 
-	client, err := s.VerifyClientCredentials(ctx, clientID, clientSecret, tx)
+	client, err := s.verifyClientCredentialsInternal(ctx, clientID, clientSecret, tx)
 	if err != nil {
 		return "", "", "", 0, err
 	}
@@ -342,7 +327,7 @@ func (s *OidcService) createTokenFromRefreshToken(ctx context.Context, refreshTo
 		tx.Rollback()
 	}()
 
-	_, err = s.VerifyClientCredentials(ctx, clientID, clientSecret, tx)
+	_, err = s.verifyClientCredentialsInternal(ctx, clientID, clientSecret, tx)
 	if err != nil {
 		return "", "", 0, err
 	}
@@ -401,7 +386,7 @@ func (s *OidcService) IntrospectToken(ctx context.Context, clientID, clientSecre
 		return introspectDto, &common.OidcMissingClientCredentialsError{}
 	}
 
-	_, err = s.VerifyClientCredentials(ctx, clientID, clientSecret, s.db)
+	_, err = s.verifyClientCredentialsInternal(ctx, clientID, clientSecret, s.db)
 	if err != nil {
 		return introspectDto, err
 	}
@@ -999,7 +984,7 @@ func (s *OidcService) getCallbackURL(urls []string, inputCallbackURL string) (ca
 }
 
 func (s *OidcService) CreateDeviceAuthorization(ctx context.Context, input dto.OidcDeviceAuthorizationRequestDto) (*dto.OidcDeviceAuthorizationResponseDto, error) {
-	client, err := s.VerifyClientCredentials(ctx, input.ClientID, input.ClientSecret, s.db)
+	client, err := s.verifyClientCredentialsInternal(ctx, input.ClientID, input.ClientSecret, s.db)
 	if err != nil {
 		return nil, err
 	}
@@ -1095,23 +1080,11 @@ func (s *OidcService) VerifyDeviceCode(ctx context.Context, userCode string, use
 	}
 
 	if !hasAuthorizedClient {
-		userAuthorizedClient := model.UserAuthorizedOidcClient{
-			UserID:   userID,
-			ClientID: deviceAuth.ClientID,
-			Scope:    deviceAuth.Scope,
+		err := s.createAuthorizedClientInternal(ctx, deviceAuth.ClientID, userID, deviceAuth.Scope, tx)
+		if err != nil {
+			return err
 		}
 
-		if err := tx.WithContext(ctx).Create(&userAuthorizedClient).Error; err != nil {
-			if !errors.Is(err, gorm.ErrDuplicatedKey) {
-				return err
-			}
-			// If duplicate, update scope
-			if err := tx.WithContext(ctx).Model(&model.UserAuthorizedOidcClient{}).
-				Where("user_id = ? AND client_id = ?", userID, deviceAuth.ClientID).
-				Update("scope", deviceAuth.Scope).Error; err != nil {
-				return err
-			}
-		}
 		s.auditLogService.Create(ctx, model.AuditLogEventNewDeviceCodeAuthorization, ipAddress, userAgent, userID, model.AuditLogData{"clientName": deviceAuth.Client.Name}, tx)
 	} else {
 		s.auditLogService.Create(ctx, model.AuditLogEventDeviceCodeAuthorization, ipAddress, userAgent, userID, model.AuditLogData{"clientName": deviceAuth.Client.Name}, tx)
@@ -1188,7 +1161,25 @@ func (s *OidcService) createRefreshToken(ctx context.Context, clientID string, u
 	return refreshToken, nil
 }
 
-func (s *OidcService) VerifyClientCredentials(ctx context.Context, clientID, clientSecret string, tx *gorm.DB) (model.OidcClient, error) {
+func (s *OidcService) createAuthorizedClientInternal(ctx context.Context, userID string, clientID string, scope string, tx *gorm.DB) error {
+	userAuthorizedClient := model.UserAuthorizedOidcClient{
+		UserID:   userID,
+		ClientID: clientID,
+		Scope:    scope,
+	}
+
+	err := tx.WithContext(ctx).
+		Clauses(clause.OnConflict{
+			Columns:   []clause.Column{{Name: "user_id"}, {Name: "client_id"}},
+			DoUpdates: clause.AssignmentColumns([]string{"scope"}),
+		}).
+		Create(&userAuthorizedClient).
+		Error
+
+	return err
+}
+
+func (s *OidcService) verifyClientCredentialsInternal(ctx context.Context, clientID, clientSecret string, tx *gorm.DB) (model.OidcClient, error) {
 	if clientID == "" {
 		return model.OidcClient{}, &common.OidcMissingClientCredentialsError{}
 	}