diff --git a/env.yml b/env.yml
index 5416ccca..349b6750 100644
--- a/env.yml
+++ b/env.yml
@@ -27,6 +27,8 @@ dependencies:
   - pandoc=3.1
   # Workflow dependencies: ANTs
   - ants=2.5
+  # Workflow dependencies: Convert3d
+  - convert3d=1.4
   # Workflow dependencies: FSL (versions pinned in 6.0.7.7)
   - fsl-bet2=2111.4
   - fsl-flirt=2111.2