diff --git a/tox.ini b/tox.ini
index 2f262f4df2..ee82ee07db 100644
--- a/tox.ini
+++ b/tox.ini
@@ -36,6 +36,7 @@ deps =
     oldestdeps: astropy==4.0
     oldestdeps: numpy==1.16
     oldestdeps: matplotlib==3.3.*
+    oldestdeps: pyvo==1.1
     cov: codecov
 
 extras =