Index: src/wp-content/themes/twentyfifteen/style.css
===================================================================
--- src/wp-content/themes/twentyfifteen/style.css	(revision 49793)
+++ src/wp-content/themes/twentyfifteen/style.css	(working copy)
@@ -3373,12 +3373,19 @@
 	}
 
 	.entry-content h5,
+	.entry-summary h5,
+	.page-content h5,
+	.comment-content h5 {
+		font-size: 18px;
+		font-size: 1.7rem;
+		line-height: 1.2353;
+		margin-top: 3.2941em;
+		margin-bottom: 1.6471em;
+	}
+
 	.entry-content h6,
-	.entry-summary h5,
 	.entry-summary h6,
-	.page-content h5,
 	.page-content h6,
-	.comment-content h5,
 	.comment-content h6 {
 		font-size: 17px;
 		font-size: 1.7rem;