diff --git a/asm/src/main/java/dev/openrs2/asm/ClassNodeRemapper.kt b/asm/src/main/java/dev/openrs2/asm/ClassNodeRemapper.kt
index 99195ef9..3ab9701f 100644
--- a/asm/src/main/java/dev/openrs2/asm/ClassNodeRemapper.kt
+++ b/asm/src/main/java/dev/openrs2/asm/ClassNodeRemapper.kt
@@ -63,8 +63,8 @@ private fun Remapper.mapFrameType(type: Any): Any {
 private fun AbstractInsnNode.remap(remapper: Remapper) {
     when (this) {
         is FrameNode -> {
-            local = local.map(remapper::mapFrameType)
-            stack = stack.map(remapper::mapFrameType)
+            local = local?.map(remapper::mapFrameType)
+            stack = stack?.map(remapper::mapFrameType)
         }
         is FieldInsnNode -> {
             val originalOwner = owner