diff --git a/extra_markdown.tpl b/extra_markdown.tpl
index bdcb2ff16c32cb8b5cbfd74f2b9440d946d484d1..8d2385b38b6ab8d47fa56fa4bb92f2f9c162b772 100644
--- a/extra_markdown.tpl
+++ b/extra_markdown.tpl
@@ -32,7 +32,9 @@ window.addEventListener('load', function() {
 {% endblock %}
 
 {% block data_svg %}
-{% if cell.metadata.attributes and cell.metadata.attributes.editable %}
+{% if cell.metadata.attributes and cell.metadata.attributes.editable == 'false' %}
+{{ super() }}
+{% else %}
 <pre class="thebelab-code" data-executable="true" data-language="python">{{cell.source}}</pre>
 <div class="thebelab-output" data-output="true" markdown="1">
 {{ super() }}
@@ -40,8 +42,6 @@ window.addEventListener('load', function() {
 <button class="thebelab-button thebelab-activate-button" onclick="initThebelab()">
   Enable live code
 </button>
-{% else %}
-{{ super() }}
 {% endif %}
 {% endblock %}
 
diff --git a/src/1_einstein_model.md b/src/1_einstein_model.md
index ea67e659d9be29f80135c370dc5c2ddeae250e01..0b83d05cd227c972c507c40f5437ef2e643f373d 100644
--- a/src/1_einstein_model.md
+++ b/src/1_einstein_model.md
@@ -43,7 +43,7 @@ _(based on chapter 2.1 of the book)_
 
 Let us look at the heat capacities of different chemical elements[^1]:
 
-```python
+```{python editable=false}
 elements = pandas.read_json('elements.json')
 elements.full_name = elements.full_name.str.capitalize()
 hovertext = elements.T.apply(
@@ -92,7 +92,7 @@ The equipartition theorem states that each of these 6 degrees of freedom contrib
 
 Things start looking more complex when we study (following Einstein) the temperature dependence of the heat capacity of diamond[^2]:
 
-```{python editable='true'}
+```python
 # Data from Einstein's paper
 T = [222.4, 262.4, 283.7, 306.4, 331.3, 358.5, 413.0, 479.2, 520.0, 879.7, 1079.7, 1258.0]
 c = [0.384, 0.578, 0.683, 0.798, 0.928, 1.069, 1.343, 1.656, 1.833, 2.671, 2.720, 2.781]
@@ -115,7 +115,7 @@ So we see that:
 
 This can be explained by considering a _quantum_ harmonic oscillator:
 
-```{python editable=true}
+```python
 import math
 from numpy.polynomial.hermite import Hermite