diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index e5fcad043e..fd30ffd00d 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -95,6 +95,7 @@ jobs:
   steps:
   - script: vcpkg --triplet x64-windows install openssl zlib
   - checkout: self
+    clean: true
     fetchDepth: 1
   - script: |
       call "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Auxiliary\Build\vcvars64.bat"