diff --git a/cmake/caches/Windows-aarch64.cmake b/cmake/caches/Windows-aarch64.cmake
index fef9e80fe1672..7b67169cc3aa3 100644
--- a/cmake/caches/Windows-aarch64.cmake
+++ b/cmake/caches/Windows-aarch64.cmake
@@ -51,7 +51,8 @@ foreach(target ${LLVM_RUNTIME_TARGETS})
   set(RUNTIMES_${target}_CMAKE_MT mt CACHE STRING "")
   set(RUNTIMES_${target}_CMAKE_SYSTEM_NAME Windows CACHE STRING "")
   set(RUNTIMES_${target}_CMAKE_BUILD_TYPE Release CACHE STRING "")
-  set(RUNTIMES_${target}_COMPILER_RT_BUILD_BUILTINS YES CACHE BOOL "")
+  # Builtins are built separately, this is the legacy path
+  set(RUNTIMES_${target}_COMPILER_RT_BUILD_BUILTINS NO CACHE BOOL "")
   set(RUNTIMES_${target}_COMPILER_RT_BUILD_CRT NO CACHE BOOL "")
   set(RUNTIMES_${target}_COMPILER_RT_BUILD_LIBFUZZER NO CACHE BOOL "")
   set(RUNTIMES_${target}_COMPILER_RT_BUILD_ORC NO CACHE BOOL "")
diff --git a/cmake/caches/Windows-x86_64.cmake b/cmake/caches/Windows-x86_64.cmake
index 7878887b3f824..2f2daa2e34307 100644
--- a/cmake/caches/Windows-x86_64.cmake
+++ b/cmake/caches/Windows-x86_64.cmake
@@ -51,7 +51,8 @@ foreach(target ${LLVM_RUNTIME_TARGETS})
   set(RUNTIMES_${target}_CMAKE_MT mt CACHE STRING "")
   set(RUNTIMES_${target}_CMAKE_SYSTEM_NAME Windows CACHE STRING "")
   set(RUNTIMES_${target}_CMAKE_BUILD_TYPE Release CACHE STRING "")
-  set(RUNTIMES_${target}_COMPILER_RT_BUILD_BUILTINS YES CACHE BOOL "")
+  # Builtins are built separately, this is the legacy path
+  set(RUNTIMES_${target}_COMPILER_RT_BUILD_BUILTINS NO CACHE BOOL "")
   set(RUNTIMES_${target}_COMPILER_RT_BUILD_CRT NO CACHE BOOL "")
   set(RUNTIMES_${target}_COMPILER_RT_BUILD_LIBFUZZER NO CACHE BOOL "")
   set(RUNTIMES_${target}_COMPILER_RT_BUILD_ORC NO CACHE BOOL "")
diff --git a/utils/build.ps1 b/utils/build.ps1
index 942c3464e8bc2..5a8840ed06090 100644
--- a/utils/build.ps1
+++ b/utils/build.ps1
@@ -2774,7 +2774,9 @@ if (-not $SkipBuild) {
 
   $InstallTo = "$($HostArch.ToolchainInstallRoot)\usr"
   foreach ($Arch in $WindowsSDKArchs) {
-    Invoke-BuildStep Build-Sanitizers Windows $Arch $InstallTo
+    if ($Arch.ShortName = "x64") {
+      Invoke-BuildStep Build-Sanitizers Windows $Arch $InstallTo
+    }
   }
 }