diff --git a/src/main/kotlin/app/revanced/patcher/Patcher.kt b/src/main/kotlin/app/revanced/patcher/Patcher.kt
index 533f89f..1fd7698 100644
--- a/src/main/kotlin/app/revanced/patcher/Patcher.kt
+++ b/src/main/kotlin/app/revanced/patcher/Patcher.kt
@@ -43,14 +43,17 @@ class Patcher(
     fun addFiles(vararg files: File, throwOnDuplicates: Boolean = false) {
         for (file in files) {
             val dexFile = MultiDexIO.readDexFile(true, files[0], NAMER, null, null)
+            val classes = mutableListOf<String>()
             for (classDef in dexFile.classes) {
-                if (cache.classes.any { it.type == classDef.type }) {
-                    // TODO: Use logger and warn about duplicate classes
+                if (classes.contains(classDef.type)) {
                     if (throwOnDuplicates)
                         throw Exception("Class ${classDef.type} has already been added to the patcher.")
+                    continue
                 }
                 cache.classes.add(classDef)
+                classes.add(classDef.type)
             }
+            classes.clear()
         }
     }
     /**