diff --git a/tox.ini b/tox.ini
index 52e3ac8..6a62c99 100644
--- a/tox.ini
+++ b/tox.ini
@@ -64,7 +64,10 @@ recreate = true
 alwayscopy=true
 package = editable-legacy
 deps =
-       -r requirements.txt
+    jsonschema
+    rcsb.utils.chemref>=0.91
+    jsondiff>=1.2.0
+    -r requirements.txt
 commands =
     echo "Starting {envname}"
     {envpython} -V
@@ -97,6 +100,9 @@ platform=
        macos: darwin
        linux: linux
 deps =
+    jsonschema
+    rcsb.utils.chemref>=0.91
+    jsondiff>=1.2.0
     pylint
     -r requirements.txt
 commands =