diff --git a/.yamato/build_classlibs_win.yml b/.yamato/build_classlibs_win.yml
new file mode 100644
index 00000000000000..e9981dbe0e6481
--- /dev/null
+++ b/.yamato/build_classlibs_win.yml
@@ -0,0 +1,20 @@
+name: Build Classlibs Windows
+
+agent:
+  type: Unity::VM
+  image: platform-foundation/windows-vs2019-il2cpp-bokken:stable
+  flavor: b1.xlarge
+
+commands:
+  - .yamato/scripts/build_classlibs.bat
+
+triggers:
+  pull_requests:
+    - targets:
+        only:
+          - "unity-main"
+
+artifacts: 
+  win64:
+    paths:
+      - incomingbuilds\**
\ No newline at end of file
diff --git a/.yamato/build_windows_x64.yml b/.yamato/build_windows_x64.yml
index 2f230462b05917..e7679a0efab9d5 100644
--- a/.yamato/build_windows_x64.yml
+++ b/.yamato/build_windows_x64.yml
@@ -8,6 +8,12 @@ agent:
 commands:
   - .yamato/scripts/build_win.bat
 
+triggers:
+  pull_requests:
+    - targets:
+        only:
+          - "unity-main"
+
 artifacts: 
   win64:
     paths:
diff --git a/.yamato/scripts/build_classlibs.bat b/.yamato/scripts/build_classlibs.bat
new file mode 100644
index 00000000000000..3f6e0dfc0dc569
--- /dev/null
+++ b/.yamato/scripts/build_classlibs.bat
@@ -0,0 +1,22 @@
+@echo OFF
+
+if not exist "incomingbuilds" mkdir "incomingbuilds"
+
+for %%x IN ("windows", "OSX", "Linux") do (
+    CALL :EchoAndExecute build.cmd libs -os %%x -c release
+    if NOT %errorlevel% == 0 (
+        echo "build failed"
+        EXIT /B %errorlevel%
+    )
+    if not exist "incomingbuilds/coreclrjit-%%x" mkdir "incomingbuilds/coreclrjit-%%x"
+
+    CALL :EchoAndExecute xcopy /s /e /h /y "artifacts/bin/runtime/net7.0-%%x-Release-x64" "incomingbuilds/coreclrjit-%%x"
+    CALL :EchoAndExecute taskkill /IM "dotnet.exe" /F
+    CALL :EchoAndExecute build.cmd -clean
+)
+EXIT /B %ERRORLEVEL%
+
+:EchoAndExecute
+ECHO %*
+CALL %*
+GOTO :EOF
diff --git a/.yamato/scripts/build_win.bat b/.yamato/scripts/build_win.bat
index 7cb15792509d51..79ebdc83e32d3f 100644
--- a/.yamato/scripts/build_win.bat
+++ b/.yamato/scripts/build_win.bat
@@ -1,5 +1,8 @@
 @echo off
-build.cmd -subset clr -a x64 -c release
+setlocal
+
+
+powershell -ExecutionPolicy ByPass -NoProfile -Command "& 'eng\build.ps1'" -subset clr -a x64 -c release
 
 if NOT %errorlevel% == 0 (
  echo "build failed"