diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -289,6 +289,7 @@
   AArch64
   AMDGPU
   ARM
+  AVR
   BPF
   Hexagon
   Lanai