diff --git a/.travis.yml b/.travis.yml
index 5354d01f..32095e57 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -217,6 +217,7 @@ install:
   - pushd $HOME
   - if [ -d "$HOME/vcpkg/.git" ] ; then echo vcpkg cached ; else rm -rf vcpkg ; git clone https://github.com/Microsoft/vcpkg ; fi
   - cd vcpkg
+  - git checkout .
   - git pull
   - if [ "${USE_VCPKG}" = true ] ; then ./bootstrap-vcpkg.sh ; fi
   - if [ "${USE_VCPKG}" = true ] ; then echo "set(VCPKG_BUILD_TYPE release)" >> triplets/x64-osx.cmake ; fi
@@ -226,6 +227,7 @@ install:
   #- if [ "${USE_VCPKG}" = true ] && [[ ! -z "${CUDACXX}" ]] ; then travis_wait 45 ./vcpkg install opencv[ffmpeg,cuda] --recurse; fi
   #- if [ "${USE_VCPKG}" = true ] && [[ -z "${CUDACXX}" ]] ; then travis_wait 45 ./vcpkg install opencv[ffmpeg] --recurse; fi
   - if [ "${USE_VCPKG}" = true ] ; then travis_wait 45 ./vcpkg install opencv[ffmpeg] --recurse; fi
+  - if [ "${USE_VCPKG}" = true ] ; then rm -rf buildtrees; fi
   - popd
 
 before_script:
diff --git a/appveyor.yml b/appveyor.yml
index 380feba4..2abab7cd 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -57,6 +57,7 @@ install:
   - if [%COMPILER%]==[cygwin] %CYGSH% 'make install'
   - if [%COMPILER%]==[cygwin] cd %WORKSPACE%
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] cd %VCPKG_ROOT%
+  - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] git checkout .
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] git pull
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] .\bootstrap-vcpkg.bat
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] echo set(VCPKG_BUILD_TYPE release) >> triplets\%VCPKG_DEFAULT_TRIPLET%.cmake
@@ -64,6 +65,7 @@ install:
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] vcpkg install stb pthreads --recurse
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] vcpkg install ffmpeg --recurse
   - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] vcpkg install opencv[ffmpeg] --recurse ## opencv[ffmpeg,cuda] is too big to build, timing out (>1h). We use plain openCV also for CUDA builds (toolchain can manage this strange situation anyway)
+  - if [%COMPILER%]==[vs] if NOT [%USE_INTEGRATED_LIBS%]==[yes] rmdir "buildtrees" /S /Q
   - cd %WORKSPACE%\darknet\
   - if [%COMPILER%]==[cygwin] mkdir build_debug && cd build_debug
   - if [%COMPILER%]==[cygwin] %CYGSH% 'cmake .. -G "Unix Makefiles" -DCMAKE_BUILD_TYPE="Debug"'