diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a702299..444fc64 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,6 +24,7 @@ jobs:
         with:
           cache-type: 'build'
           source-dir: 'lectures'
+          save-cache: 'true'
       
       - name: Build PDF
         uses: quantecon/actions/build-lectures@v0.5.0
diff --git a/lectures/intro.md b/lectures/intro.md
index 7b3607e..cd32778 100644
--- a/lectures/intro.md
+++ b/lectures/intro.md
@@ -11,7 +11,7 @@ kernelspec:
 
 # (TEST) A First Course in Quantitative Economics with Python
 
-This lecture series provides an introduction to quantitative economics using Python. 
+This lecture series provides an introduction to quantitative economics using Python.
 
 ```{tableofcontents}
 ```