diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
--- a/clang/CMakeLists.txt
+++ b/clang/CMakeLists.txt
@@ -233,7 +233,7 @@
 set(ENABLE_X86_RELAX_RELOCATIONS OFF CACHE BOOL
     "enable x86 relax relocations by default")
 
-set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER FALSE CACHE BOOL
+set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER TRUE CACHE BOOL
   "Enable the experimental new pass manager by default.")
 
 # TODO: verify the values against LangStandards.def?