diff --git a/src/Patches.php b/src/Patches.php
index bb6859be..d499470b 100644
--- a/src/Patches.php
+++ b/src/Patches.php
@@ -182,7 +182,7 @@ public function gatherPatches(PackageEvent $event) {
 
     // Merge installed patches from dependencies that did not receive an update.
     foreach ($this->installedPatches as $patches) {
-      $this->patches = array_merge_recursive($this->patches, $patches);
+      $this->patches = $this->arrayMergeRecursiveDistinct($this->patches, $patches);
     }
 
     // If we're in verbose mode, list the projects we're going to patch.