diff --git a/pgweb/docs/views.py b/pgweb/docs/views.py
index 04a065f6..db7e76e6 100644
--- a/pgweb/docs/views.py
+++ b/pgweb/docs/views.py
@@ -91,11 +91,11 @@ class _VersionPdfWrapper(Version):
 		self.a4pdf = self._find_pdf('A4')
 		self.uspdf = self._find_pdf('US')
 		# Some versions have, ahem, strange index filenames
-		if self.__version.tree < 6.4:
+		if self.__version.tree < Decimal('6.4'):
 			self.indexname = 'book01.htm'
-		elif self.__version.tree < 7.0:
+		elif self.__version.tree < Decimal('7.0'):
 			self.indexname = 'postgres.htm'
-		elif self.__version.tree < 7.2:
+		elif self.__version.tree < Decimal('7.2'):
 			self.indexname = 'postgres.html'
 		else:
 			self.indexname = 'index.html'