diff --git a/UltiSnips/all.snippets b/UltiSnips/all.snippets
index 273b631..fb3b8ee 100644
--- a/UltiSnips/all.snippets
+++ b/UltiSnips/all.snippets
@@ -4,8 +4,17 @@ endsnippet
 
 global !p
 comment=vim.current.buffer.options['commentstring'].strip()
+
 def commentbefore():
-	return comment[0:comment.find('%s')].strip() + ' '
+	commentbefore = comment[0:comment.find('%s')].strip()
+	row, col = vim.current.window.cursor
+	row -= 1
+	col -= 1
+	line = vim.current.buffer[row]
+	if (col - 1) >= 0 and commentbefore == line[col - 1:len(commentbefore)]:
+		return ''
+	return commentbefore + ' '
+
 def commentafter():
 	after=comment[comment.find('%s')+2:].strip()
 	if 0 < len(after):