diff --git a/Parsedown.php b/Parsedown.php
index 1d9839b..5e4a6e2 100644
--- a/Parsedown.php
+++ b/Parsedown.php
@@ -505,7 +505,8 @@ class Parsedown
                 return;
             }
 
-            $text = trim($Line['text'], '# ');
+            $text = trim($Line['text'], '#');
+            $text = trim($text, ' ');
 
             $Block = array(
                 'element' => array(
diff --git a/test/data/atx_heading.html b/test/data/atx_heading.html
index 751f873..94c3825 100644
--- a/test/data/atx_heading.html
+++ b/test/data/atx_heading.html
@@ -6,4 +6,6 @@
 <h6>h6</h6>
 <p>####### not a heading</p>
 <h1>closed h1</h1>
-<p>#</p>
\ No newline at end of file
+<p>#</p>
+<h1># of levels</h1>
+<h1># of levels #</h1>
\ No newline at end of file
diff --git a/test/data/atx_heading.md b/test/data/atx_heading.md
index ad97b44..62fdd6c 100644
--- a/test/data/atx_heading.md
+++ b/test/data/atx_heading.md
@@ -14,4 +14,8 @@
 
 # closed h1 #
 
-#
\ No newline at end of file
+#
+
+# # of levels
+
+# # of levels # #
\ No newline at end of file