diff --git a/environment.yml b/environment.yml
index 8272a0c48..a173c1918 100644
--- a/environment.yml
+++ b/environment.yml
@@ -7,7 +7,7 @@ dependencies:
   - pip
   - pip:
     - jupyter-book==1.0.4post1
-    - quantecon-book-theme==0.15.0
+    - quantecon-book-theme==0.15.1
     - sphinx-tojupyter==0.3.1
     - sphinxext-rediraffe==0.3.0
     - sphinx-exercise==1.0.1
diff --git a/lectures/_config.yml b/lectures/_config.yml
index 069af81d3..bb8173d0a 100644
--- a/lectures/_config.yml
+++ b/lectures/_config.yml
@@ -44,7 +44,40 @@ sphinx:
     nb_render_image_options:
       width: 80%
     nb_code_prompt_show: "Show {type}"
+    nb_merge_streams: true
+    nb_mime_priority_overrides: [
+       # HTML
+       ['html', 'application/vnd.jupyter.widget-view+json', 10],
+       ['html', 'application/javascript', 20],
+       ['html', 'text/html', 30],
+       ['html', 'text/latex', 40],
+       ['html', 'image/svg+xml', 50],
+       ['html', 'image/png', 60],
+       ['html', 'image/jpeg', 70],
+       ['html', 'text/markdown', 80],
+       ['html', 'text/plain', 90],
+       # Jupyter Notebooks
+       ['jupyter', 'application/vnd.jupyter.widget-view+json', 10],
+       ['jupyter', 'application/javascript', 20],
+       ['jupyter', 'text/html', 30],
+       ['jupyter', 'text/latex', 40],
+       ['jupyter', 'image/svg+xml', 50],
+       ['jupyter', 'image/png', 60],
+       ['jupyter', 'image/jpeg', 70],
+       ['jupyter', 'text/markdown', 80],
+       ['jupyter', 'text/plain', 90],
+       # LaTeX
+       ['latex', 'text/latex', 10],
+       ['latex', 'application/pdf', 20],
+       ['latex', 'image/png', 30],
+       ['latex', 'image/jpeg', 40],
+       ['latex', 'text/markdown', 50],
+       ['latex', 'text/plain', 60],
+       # Link Checker
+       ['linkcheck', 'text/plain', 10],
+     ]
     suppress_warnings: [mystnb.unknown_mime_type, myst.domains]
+    # sphinx-proof
     proof_minimal_theme: true
     # -------------
     html_js_files:
@@ -63,6 +96,7 @@ sphinx:
       header_organisation: QuantEcon
       repository_url: https://github.com/QuantEcon/lecture-python-intro
       nb_repository_url: https://github.com/QuantEcon/lecture-python-intro.notebooks
+      path_to_docs: lectures
       twitter: quantecon
       twitter_logo_url: https://assets.quantecon.org/img/qe-twitter-logo.png
       og_logo_url: https://assets.quantecon.org/img/qe-og-logo.png