diff --git a/llvm/lib/Support/BLAKE3/CMakeLists.txt b/llvm/lib/Support/BLAKE3/CMakeLists.txt
index 763eba5ba50f20f36b780a35c3e78f9149e05251..4746c2f38f16085eb91efea025fa01f5ee9a183e 100644
--- a/llvm/lib/Support/BLAKE3/CMakeLists.txt
+++ b/llvm/lib/Support/BLAKE3/CMakeLists.txt
@@ -11,7 +11,8 @@ set(LLVM_BLAKE3_FILES
 # version using C intrinsics. The assembly versions are generally
 # preferred. They perform better, they perform more consistently across
 # different compilers, and they build more quickly."
-if (CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|AMD64)$")
+# FIXME: Figure out what is wrong with the builders when using the assembly files.
+if (FALSE)#CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|AMD64)$")
   if (MSVC)
     list(APPEND LLVM_BLAKE3_FILES
       BLAKE3/blake3_sse2_x86-64_windows_msvc.asm
@@ -36,7 +37,7 @@ if (CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|AMD64)$")
   endif()
 endif()
 
-if (CMAKE_SYSTEM_PROCESSOR MATCHES "arm")
+if (CMAKE_SYSTEM_PROCESSOR MATCHES "^(arm|aarch)")
   list(APPEND LLVM_BLAKE3_FILES
     BLAKE3/blake3_neon.c
   )
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 4cc0a97032daaae4ed8492b635f5aa4d9bcc7f45..b4ae4e89dab675ac7d4680215825239bfa03ab62 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -106,6 +106,9 @@ add_subdirectory(BLAKE3)
 if (MSVC)
   enable_language(ASM_MASM)
 endif()
+# FIXME: Figure out what is wrong with the builders when using the assembly files.
+add_definitions(-DBLAKE3_NO_AVX512 -DBLAKE3_NO_AVX2 -DBLAKE3_NO_SSE41 -DBLAKE3_NO_SSE2)
+
 
 add_llvm_component_library(LLVMSupport
   AArch64TargetParser.cpp