diff --git a/devtools/conda-envs/release-build.yml b/devtools/conda-envs/release-build.yml
index 0d44961..7d14a3c 100644
--- a/devtools/conda-envs/release-build.yml
+++ b/devtools/conda-envs/release-build.yml
@@ -23,6 +23,7 @@ dependencies:
     # Molecule building
     - mbuild
     - rdkit
+    - openeye-toolkits # TODO: consider making this optional?
 
     # Visualization
     - pillow