diff --git a/pkg/database/pool_reference.go b/pkg/database/pool_reference.go
index e675a07..fed3315 100644
--- a/pkg/database/pool_reference.go
+++ b/pkg/database/pool_reference.go
@@ -40,7 +40,7 @@ func CreatePoolReference(ctx context.Context, poolID models.PoolID, sourceID mod
 		return models.PoolReference{}, utils.HandleError(ctx, span, localLogger, &otterError.EntityValidationFailed{Reason: otterError.PoolIDIsWrongLength})
 	}
 
-	if sourceID == "" {
+	if len(sourceID) == 0 {
 		return models.PoolReference{}, utils.HandleError(ctx, span, localLogger, &otterError.EntityValidationFailed{Reason: otterError.SourceIDIsEmpty})
 	}
 
@@ -100,7 +100,7 @@ func DeletePoolReference(ctx context.Context, poolID models.PoolID, sourceID mod
 		return utils.HandleError(ctx, span, localLogger, &otterError.EntityValidationFailed{Reason: otterError.PostIDIsWrongLength})
 	}
 
-	if sourceID == "" {
+	if len(sourceID) == 0 {
 		return utils.HandleError(ctx, span, localLogger, &otterError.EntityValidationFailed{Reason: otterError.SourceIDIsEmpty})
 	}