diff --git a/environment_no_cuda.yml b/environment_no_cuda.yml
index 2adee7a89..e60260bc1 100644
--- a/environment_no_cuda.yml
+++ b/environment_no_cuda.yml
@@ -11,7 +11,7 @@ channels:
 
 dependencies:
     # Packages SLEAP uses directly
-    - conda-forge::attrs >=21.2.0  #,<=21.4.0
+    - conda-forge::attrs >=21.2.0, <=21.4.0
     - conda-forge::cattrs ==1.1.1
     - conda-forge::imageio-ffmpeg # Required for imageio to read/write videos with ffmpeg
     - conda-forge::jsmin