diff --git a/tox.ini b/tox.ini
index 38f83b2..a893ad1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,7 +23,7 @@ pip_pre = true
 # Note that we install all dependencies in all environments to catch any
 # side effects and make sure all test suites pass with all packages
 deps =
-    astropy[all,test]
+    astropy[all,test] @ git+https://github.com/astropy/astropy.git
 
     asdf_astropy-!dev,all-!dev: asdf_astropy[test]
     asdf_astropy-dev,all-dev: asdf_astropy[test] @ git+https://github.com/astropy/asdf-astropy.git