diff --git a/src/SelectTree.php b/src/SelectTree.php
index e7f9716..9788bb8 100644
--- a/src/SelectTree.php
+++ b/src/SelectTree.php
@@ -313,6 +313,8 @@ public function prepend(Closure|array|null $prepend = null): static
 
         if (is_array($this->prepend) && isset($this->prepend['name'], $this->prepend['value'])) {
             $this->prepend['value'] = (string) $this->prepend['value'];
+        } else if (is_null($this->prepend)){
+            # Avoid throwing an exception in case $prepend is explicitly set to null, or a Closure evaluates to null.
         } else {
             throw new InvalidArgumentException('The provided prepend value must be an array with "name" and "value" keys.');
         }
@@ -326,6 +328,8 @@ public function append(Closure|array|null $append = null): static
 
         if (is_array($this->append) && isset($this->append['name'], $this->append['value'])) {
             $this->append['value'] = (string) $this->append['value'];
+        } else if (is_null($this->append)) {
+            // Avoid throwing an exception in case $append is explicitly set to null, or a Closure evaluates to null.
         } else {
             throw new \InvalidArgumentException('The provided append value must be an array with "name" and "value" keys.');
         }