diff --git a/devtools/conda-envs/test_env.yaml b/devtools/conda-envs/test_env.yaml
index e769894..64027f0 100644
--- a/devtools/conda-envs/test_env.yaml
+++ b/devtools/conda-envs/test_env.yaml
@@ -22,6 +22,7 @@ dependencies:
   - sphinx_rtd_theme
   - sphinx-argparse
   - m2r2
+  - docutils>=0.18.1,<0.21
 
   # Pip-only installs
   #- pip:
diff --git a/docs/requirements b/docs/requirements
index 39d3b8f..d3d5b4c 100644
--- a/docs/requirements
+++ b/docs/requirements
@@ -5,4 +5,5 @@ matplotlib
 sphinx-argparse
 sphinx_rtd_theme
 m2r2
+docutils>=0.18.1,<0.21