diff --git a/setup.py b/setup.py
index bc26c64b..81a1b06c 100644
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,7 @@
     python_requires='>=3.6',
     install_requires=[
         'docutils',
-        'jinja2~=2.11',
+        'jinja2',
         'nbconvert!=5.4',
         'traitlets',
         'nbformat',
diff --git a/src/nbsphinx.py b/src/nbsphinx.py
index 8b02f20a..9374ac9b 100644
--- a/src/nbsphinx.py
+++ b/src/nbsphinx.py
@@ -241,9 +241,9 @@
 
 {% block markdowncell %}
 {%- if 'nbsphinx-gallery' in cell.metadata
-    or 'nbsphinx-gallery' in cell.metadata.tags
+    or 'nbsphinx-gallery' in cell.metadata.get('tags', [])
     or 'nbsphinx-toctree' in cell.metadata
-    or 'nbsphinx-toctree' in cell.metadata.tags %}
+    or 'nbsphinx-toctree' in cell.metadata.get('tags', []) %}
 {{ cell | extract_gallery_or_toctree }}
 {%- else %}
 {{ cell | save_attachments or super() | replace_attachments }}
@@ -279,7 +279,7 @@
 
 {% block footer %}
 
-{% if 'application/vnd.jupyter.widget-state+json' in nb.metadata.widgets %}
+{% if 'application/vnd.jupyter.widget-state+json' in nb.metadata.get('widgets', {})%}
 
 .. raw:: html