diff --git a/.github/workflows/build_docs.yml b/.github/workflows/build_docs.yml
index 30a7060..19a955b 100644
--- a/.github/workflows/build_docs.yml
+++ b/.github/workflows/build_docs.yml
@@ -2,8 +2,14 @@
  on:
    push:
      branches:
-     - master
      - main
+   workflow_dispatch:
+     inputs:
+       version:
+         description: Manual Doc Build Reason
+         default: test
+         required: false
+
  jobs:
    docs:
      name: CI (${{ matrix.os }}-${{ matrix.environment-file }})
@@ -13,7 +19,7 @@
      strategy:
        matrix:
          os: ['ubuntu-latest']
-         environment-file: [ci/39-latest.yaml]
+         environment-file: [ci/312-latest.yaml]
          experimental: [false]
      defaults:
        run:
diff --git a/ci/312-latest.yaml b/ci/312-latest.yaml
index 7bbcb12..0e9984b 100644
--- a/ci/312-latest.yaml
+++ b/ci/312-latest.yaml
@@ -25,3 +25,9 @@ dependencies:
   - scikit-learn>=0.17.1
   - seaborn>=0.7.0
   - statsmodels>=0.6.1
+  # for docs build action (this env only)
+  - nbsphinx
+  - numpydoc
+  - sphinx>=1.4.3
+  - sphinxcontrib-bibtex<2.0.0
+  - sphinx_bootstrap_theme
diff --git a/ci/39-latest.yaml b/ci/39-latest.yaml
index dadbfe7..fc5eb3b 100644
--- a/ci/39-latest.yaml
+++ b/ci/39-latest.yaml
@@ -25,9 +25,3 @@ dependencies:
   - scikit-learn>=0.17.1
   - seaborn>=0.7.0
   - statsmodels>=0.6.1
-  # for docs build action (this env only)
-  - nbsphinx
-  - numpydoc
-  - sphinx>=1.4.3
-  - sphinxcontrib-bibtex<2.0.0
-  - sphinx_bootstrap_theme