diff --git a/backend/internal/service/auth_oauth_first_bind.go b/backend/internal/service/auth_oauth_first_bind.go
index b0da5069..aa06e59f 100644
--- a/backend/internal/service/auth_oauth_first_bind.go
+++ b/backend/internal/service/auth_oauth_first_bind.go
@@ -61,7 +61,7 @@ func (s *AuthService) applyProviderDefaultSettingsOnFirstBind(
 	if err := client.Driver().Exec(
 		ctx,
 		`INSERT INTO user_provider_default_grants (user_id, provider_type, grant_reason)
-VALUES (?, ?, ?)
+VALUES ($1, $2, $3)
 ON CONFLICT (user_id, provider_type, grant_reason) DO NOTHING`,
 		[]any{userID, strings.TrimSpace(providerType), "first_bind"},
 		&result,
diff --git a/backend/internal/service/auth_service.go b/backend/internal/service/auth_service.go
index c3d9cc32..a40fd825 100644
--- a/backend/internal/service/auth_service.go
+++ b/backend/internal/service/auth_service.go
@@ -855,7 +855,7 @@ func (s *AuthService) hasProviderGrantRecord(
 
 	rows, err := s.entClient.QueryContext(
 		ctx,
-		`SELECT 1 FROM user_provider_default_grants WHERE user_id = ? AND provider_type = ? AND grant_reason = ? LIMIT 1`,
+		`SELECT 1 FROM user_provider_default_grants WHERE user_id = $1 AND provider_type = $2 AND grant_reason = $3 LIMIT 1`,
 		userID,
 		strings.TrimSpace(providerType),
 		strings.TrimSpace(grantReason),