diff --git a/environment.yml b/environment.yml
index 54d3b45..a736024 100644
--- a/environment.yml
+++ b/environment.yml
@@ -5,6 +5,6 @@ channels:
 
 dependencies:
   - python==3.11.*
-  - nodejs>=20.0
+  - nodejs>=18.0
   - libwebp==1.3.2
-  - mystmd==1.2.0
+  - mystmd==1.1.56