diff --git a/src/diagrams/sequenceDiagram/parser/sequenceDiagram.jison b/src/diagrams/sequenceDiagram/parser/sequenceDiagram.jison
index 32029b78b..f98f935fe 100644
--- a/src/diagrams/sequenceDiagram/parser/sequenceDiagram.jison
+++ b/src/diagrams/sequenceDiagram/parser/sequenceDiagram.jison
@@ -64,7 +64,9 @@
 %% /* language grammar */
 
 start
-	: SD document { yy.apply($2);return $2; }
+	: SPACE start
+	| NL start
+	| SD document { yy.apply($2);return $2; }
 	;
 
 document
diff --git a/test/examples/leadingComments.html b/test/examples/leadingComments.html
index 02366a89a..dbb0af2bc 100644
--- a/test/examples/leadingComments.html
+++ b/test/examples/leadingComments.html
@@ -22,7 +22,7 @@
             B                          -->C["#9829; ;^; #60;"]
         </div>
         <div class="mermaid" id="i211">
-
+            %% Example diagram
             sequenceDiagram
             Ali#45;ce->>John: Hello John, how are you? #60;
             John-->>Alice: Great!#quot;