diff --git a/.appveyor.yml b/.appveyor.yml
index ddee3c59..c9703e56 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -6,7 +6,10 @@ platform:
 environment:
   matrix:
     - TOXENV: "py27"
+      PLATFORMIO_BUILD_CACHE_DIR: C:/Temp/PIO_Build_Cache_P2_{build}
+
     - TOXENV: "py36"
+      PLATFORMIO_BUILD_CACHE_DIR: C:/Temp/PIO_Build_Cache_P3_{build}
 
 install:
   - cmd: git submodule update --init --recursive