diff --git a/appveyor.yml b/appveyor.yml
index a4a24829..d029e05c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -23,6 +23,7 @@ environment:
 install:
  - "set PATH=%MINICONDA%;%MINICONDA%\\Scripts;%PATH%"
  - conda config --set always_yes yes --set changeps1 no
+ - conda config --add pinned_packages defaults::conda
  - conda clean --packages
  - conda update -q conda
  - conda info -a