diff --git a/src/functions.php b/src/functions.php
index 7b29ec4..9670132 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -70,6 +70,9 @@ function v2(
  * @param string|UuidInterface $ns The namespace (must be a valid UUID)
  *
  * @return string Version 3 UUID as a string
+ *
+ * @psalm-pure note: changing the internal factory is an edge case not covered by purity invariants,
+ *             but under constant factory setups, this method operates in functionally pure manners
  */
 function v3($ns, string $name): string
 {
@@ -93,6 +96,9 @@ function v4(): string
  * @param string|UuidInterface $ns The namespace (must be a valid UUID)
  *
  * @return string Version 5 UUID as a string
+ *
+ * @psalm-pure note: changing the internal factory is an edge case not covered by purity invariants,
+ *             but under constant factory setups, this method operates in functionally pure manners
  */
 function v5($ns, string $name): string
 {