diff --git a/wetb/hawc2/htc_contents.py b/wetb/hawc2/htc_contents.py
index 3230414b3f98a84cb7a9da8f9176b5488b223a64..9b86dd6beff8d6e38eb6ba789300e145d2bc52c1 100644
--- a/wetb/hawc2/htc_contents.py
+++ b/wetb/hawc2/htc_contents.py
@@ -209,7 +209,7 @@ class HTCOutputSection(HTCSection):
 
 
     def __str__(self, level=0):
-        s = "%sbegin %s;%s\n" % ("  "*level, self.name_, ("", "\t" + self.begin_comments)[len(self.begin_comments.strip())])
+        s = "%sbegin %s;%s\n" % ("  "*level, self.name_, ("", "\t" + self.begin_comments)[len(self.begin_comments.strip()) > 0])
         s += "".join([c.__str__(level + 1) for c in self])
         s += "".join([s.__str__(level + 1) for s in self.sensors])
         s += "%send %s;%s\n" % ("  "*level, self.name_, ("", "\t" + self.end_comments)[self.end_comments.strip() != ""])