diff --git a/.test-py3.yml b/.test-py3.yml
index bf657b153d97c3b6f0a8cc966489eab0e70e02fb..d80032887699f58f8709e50a40110298c9ccd5c6 100644
--- a/.test-py3.yml
+++ b/.test-py3.yml
@@ -4,6 +4,7 @@ channels:
  - conda-forge
  - defaults
 dependencies:
+ - pexpect
  - conda-forge::numpy
  - conda-forge::sympy
  - python=3.5