diff --git a/python/vegafusion/tests/altair_mocks/bar/diverging_stacked/mock.py b/python/vegafusion/tests/altair_mocks/bar/diverging_stacked/mock.py
index 8fbb61bd5..7e1bd976f 100644
--- a/python/vegafusion/tests/altair_mocks/bar/diverging_stacked/mock.py
+++ b/python/vegafusion/tests/altair_mocks/bar/diverging_stacked/mock.py
@@ -1,8 +1,9 @@
 # https://altair-viz.github.io/gallery/diverging_stacked_bar_chart.html
 
 import altair as alt
+import pandas as pd
 
-source = alt.pd.DataFrame([
+source = pd.DataFrame([
     {
         "question": "Question 1",
         "type": "Strongly disagree",
diff --git a/python/vegafusion/tests/altair_mocks/casestudy/falkensee/mock.py b/python/vegafusion/tests/altair_mocks/casestudy/falkensee/mock.py
index 13c727037..1dc85856e 100644
--- a/python/vegafusion/tests/altair_mocks/casestudy/falkensee/mock.py
+++ b/python/vegafusion/tests/altair_mocks/casestudy/falkensee/mock.py
@@ -1,6 +1,7 @@
 # https://altair-viz.github.io/gallery/falkensee.html
 
 import altair as alt
+import pandas as pd
 
 source = [
     {"year": "1875", "population": 1309},
@@ -55,8 +56,8 @@
     }]
 
 
-source = alt.pd.DataFrame(source)
-source2 = alt.pd.DataFrame(source2)
+source = pd.DataFrame(source)
+source2 = pd.DataFrame(source2)
 
 
 line = alt.Chart(source).mark_line(color='#333').encode(