diff --git a/recipes/science_advances.recipe b/recipes/science_advances.recipe
index e8b2925f95..dbc5192f84 100644
--- a/recipes/science_advances.recipe
+++ b/recipes/science_advances.recipe
@@ -28,13 +28,13 @@ class scienceadv(BasicNewsRecipe):
     simultaneous_downloads = 1
     browser_type = 'webengine'
 
-    extra_css = """
+    extra_css = '''
         .news-article__figure__caption, .calibre-nuked-tag-figcaption, .card-related {font-size:small;}
         .core-self-citation, .meta-panel__left-content, .news-article__hero__top-meta {font-size:small;}
         .contributors, .news-article__hero__bottom-meta, #bibliography, #elettersSection {font-size:small;}
         img {display:block; margin:0 auto;}
         .core-lede {font-style:italic; color:#202020;}
-    """
+    '''
 
     ignore_duplicate_articles = {'url'}
 
diff --git a/recipes/science_journal.recipe b/recipes/science_journal.recipe
index fb4bf66cb3..dbbed53478 100644
--- a/recipes/science_journal.recipe
+++ b/recipes/science_journal.recipe
@@ -26,13 +26,13 @@ class science(BasicNewsRecipe):
     simultaneous_downloads = 1
     browser_type = 'webengine'
 
-    extra_css = """
+    extra_css = '''
         .news-article__figure__caption, .calibre-nuked-tag-figcaption, .card-related {font-size:small;}
         .core-self-citation, .meta-panel__left-content, .news-article__hero__top-meta {font-size:small;}
         .contributors, .news-article__hero__bottom-meta, #bibliography, #elettersSection {font-size:small;}
         img {display:block; margin:0 auto;}
         .core-lede {font-style:italic; color:#202020;}
-    """
+    '''
 
     ignore_duplicate_articles = {'url'}
 
diff --git a/recipes/sciimmunol.recipe b/recipes/sciimmunol.recipe
index 8fb31e90c3..d5b1e09549 100644
--- a/recipes/sciimmunol.recipe
+++ b/recipes/sciimmunol.recipe
@@ -28,13 +28,13 @@ class scienceadv(BasicNewsRecipe):
     simultaneous_downloads = 1
     browser_type = 'webengine'
 
-    extra_css = """
+    extra_css = '''
         .news-article__figure__caption, .calibre-nuked-tag-figcaption, .card-related {font-size:small;}
         .core-self-citation, .meta-panel__left-content, .news-article__hero__top-meta {font-size:small;}
         .contributors, .news-article__hero__bottom-meta, #bibliography, #elettersSection {font-size:small;}
         img {display:block; margin:0 auto;}
         .core-lede {font-style:italic; color:#202020;}
-    """
+    '''
 
     ignore_duplicate_articles = {'url'}
 
diff --git a/recipes/scirobotics.recipe b/recipes/scirobotics.recipe
index a2a5f2ff81..b6b3f11573 100644
--- a/recipes/scirobotics.recipe
+++ b/recipes/scirobotics.recipe
@@ -26,13 +26,13 @@ class scienceadv(BasicNewsRecipe):
     simultaneous_downloads = 1
     browser_type = 'webengine'
 
-    extra_css = """
+    extra_css = '''
         .news-article__figure__caption, .calibre-nuked-tag-figcaption, .card-related {font-size:small;}
         .core-self-citation, .meta-panel__left-content, .news-article__hero__top-meta {font-size:small;}
         .contributors, .news-article__hero__bottom-meta, #bibliography, #elettersSection {font-size:small;}
         img {display:block; margin:0 auto;}
         .core-lede {font-style:italic; color:#202020;}
-    """
+    '''
 
     ignore_duplicate_articles = {'url'}
 
diff --git a/recipes/scisignaling.recipe b/recipes/scisignaling.recipe
index 77a4a9fc15..722259944a 100644
--- a/recipes/scisignaling.recipe
+++ b/recipes/scisignaling.recipe
@@ -27,13 +27,13 @@ class scienceadv(BasicNewsRecipe):
     simultaneous_downloads = 1
     browser_type = 'webengine'
 
-    extra_css = """
+    extra_css = '''
         .news-article__figure__caption, .calibre-nuked-tag-figcaption, .card-related {font-size:small;}
         .core-self-citation, .meta-panel__left-content, .news-article__hero__top-meta {font-size:small;}
         .contributors, .news-article__hero__bottom-meta, #bibliography, #elettersSection {font-size:small;}
         img {display:block; margin:0 auto;}
         .core-lede {font-style:italic; color:#202020;}
-    """
+    '''
 
     ignore_duplicate_articles = {'url'}
 
diff --git a/recipes/scistm.recipe b/recipes/scistm.recipe
index c86f27234d..62762efc91 100644
--- a/recipes/scistm.recipe
+++ b/recipes/scistm.recipe
@@ -28,13 +28,13 @@ class scienceadv(BasicNewsRecipe):
     simultaneous_downloads = 1
     browser_type = 'webengine'
 
-    extra_css = """
+    extra_css = '''
         .news-article__figure__caption, .calibre-nuked-tag-figcaption, .card-related {font-size:small;}
         .core-self-citation, .meta-panel__left-content, .news-article__hero__top-meta {font-size:small;}
         .contributors, .news-article__hero__bottom-meta, #bibliography, #elettersSection {font-size:small;}
         img {display:block; margin:0 auto;}
         .core-lede {font-style:italic; color:#202020;}
-    """
+    '''
 
     ignore_duplicate_articles = {'url'}