diff --git a/ipfix/template.py b/ipfix/template.py
index 1203e55..26cd8c1 100644
--- a/ipfix/template.py
+++ b/ipfix/template.py
@@ -187,7 +187,7 @@ def decode_from(self, buf, offset, packplan = None):
         offset += packplan.st.size
 
         # short circuit on no varlen
-        if not self.varlenslice:
+        if self.varlenslice is None:
             return (vals, offset)
 
         # direct iteration over remaining IEs
@@ -239,7 +239,7 @@ def encode_to(self, buf, offset, vals, packplan = None):
         offset += packplan.st.size
 
         # shortcircuit no varlen
-        if not self.varlenslice:
+        if self.varlenslice is None:
             return offset
 
         # direct iteration over remaining IEs