diff --git a/appveyor.yml b/appveyor.yml
index bb7f99a..0779d84 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -63,7 +63,7 @@ install:
   # compiled extensions and are not provided as pre-built wheel packages,
   # pip will build them from source using the MSVC compiler matching the
   # target Python version and architecture
-  - "%CMD_IN_ENV% pip install -e ."
+  - "%CMD_IN_ENV% pip install -e .[dev]"
 
 test_script:
   # Run the project tests