diff --git a/recipes/bloomberg-business-week.recipe b/recipes/bloomberg-business-week.recipe
index 2d68d60dcd..e13167ca14 100644
--- a/recipes/bloomberg-business-week.recipe
+++ b/recipes/bloomberg-business-week.recipe
@@ -125,7 +125,7 @@ class Bloomberg(BasicNewsRecipe):
 
         if 'abstract' in data and data['abstract'] and data['abstract'] is not None:
             subhead = '<div class="subhead"><ul><li>' + '</li><li>'.join(list(data['abstract'])) + '</li></ul></div>'
-        elif 'summary' in data and data['summary']:
+        elif data.get('summary'):
             subhead = '<div class="subhead"><p>' + data['summary'] + '</p></div>'
 
         if 'byline' in data and data['byline'] is not None:
diff --git a/recipes/bloomberg.recipe b/recipes/bloomberg.recipe
index 8b2cb982ae..02f1a9ceb0 100644
--- a/recipes/bloomberg.recipe
+++ b/recipes/bloomberg.recipe
@@ -135,7 +135,7 @@ class Bloomberg(BasicNewsRecipe):
 
         if 'abstract' in data and data['abstract'] and data['abstract'] is not None:
             subhead = '<div class="subhead"><ul><li>' + '</li><li>'.join(list(data['abstract'])) + '</li></ul></div>'
-        elif 'summary' in data and data['summary']:
+        elif data.get('summary'):
             subhead = '<div class="subhead"><p>' + data['summary'] + '</p></div>'
 
         if 'byline' in data and data['byline'] is not None:
diff --git a/recipes/tls_mag.recipe b/recipes/tls_mag.recipe
index 6bb1ef8765..8aa0b13e0a 100644
--- a/recipes/tls_mag.recipe
+++ b/recipes/tls_mag.recipe
@@ -120,7 +120,7 @@ class TLS(BasicNewsRecipe):
             if prim['byline']['text']:
                 auth = '<p class="auth"><a href="{}">'.format(prim['byline']['link']) + prim['byline']['text'] + '</a></p>\n'
 
-            if 'bookdetails' in prim and prim['bookdetails']:
+            if prim.get('bookdetails'):
                 bks += '<br>'
                 for a in prim['bookdetails']:
                     for x, y in a.items():
@@ -135,7 +135,7 @@ class TLS(BasicNewsRecipe):
 
         if 'article_data_leadimage' in data:
             i = data['article_data_leadimage']
-            if 'full_image' in i and i['full_image']:
+            if i.get('full_image'):
                 lede = '<br><img src="{}"><div class="figc">{}</div>'.format(
                     i['full_image'] + '?w600', i['imagecaption'] + ' <i>' \
                         + i['imagecredit'] + '</i>'
diff --git a/ruff-strict-pep8.toml b/ruff-strict-pep8.toml
index 90527ef705..4d78f5048e 100644
--- a/ruff-strict-pep8.toml
+++ b/ruff-strict-pep8.toml
@@ -20,7 +20,7 @@ quote-style = 'single'
 ignore = [
     'E402', 'E722', 'E741',
     'UP012', 'UP030', 'UP032', 'UP038', 'C413', 'C420',
-    'RUF001', 'RUF002', 'RUF003', 'RUF005', 'RUF010', 'RUF012', 'RUF013', 'RUF015', 'RUF019', 'RUF021', 'RUF031', 'RUF034', 'RUF100',
+    'RUF001', 'RUF002', 'RUF003', 'RUF005', 'RUF010', 'RUF012', 'RUF013', 'RUF015', 'RUF021', 'RUF031', 'RUF034', 'RUF100',
 ]
 select = [
     'E', 'F', 'I', 'W', 'INT',
diff --git a/src/calibre/library/catalogs/epub_mobi_builder.py b/src/calibre/library/catalogs/epub_mobi_builder.py
index 87a3cc7ba3..cb1b405b2e 100644
--- a/src/calibre/library/catalogs/epub_mobi_builder.py
+++ b/src/calibre/library/catalogs/epub_mobi_builder.py
@@ -2734,7 +2734,7 @@ class CatalogBuilder:
         # Thumb
         _soup = BeautifulSoup('<html>', selfClosingTags=['img'])
         thumb = _soup.new_tag('img')
-        if 'cover' in book and book['cover']:
+        if book.get('cover'):
             thumb['src'] = '../images/thumbnail_%d.jpg' % int(book['id'])
         else:
             thumb['src'] = '../images/thumbnail_default.jpg'
