diff --git a/downloadversionIRdata.py b/downloadversionIRdata.py
index 332126e4200205ba98a54b5bb6e8d1b3a6518048..80ab58be7507e11711618365b67ffe11d85b20b1 100644
--- a/downloadversionIRdata.py
+++ b/downloadversionIRdata.py
@@ -134,7 +134,7 @@ def read_program(timestamp_start,timestamp_end=0,tol=60):
     read_program()
     """
     program_url = 'http://archive-webapi.ipp-hgw.mpg.de/programs.json?from'
-    if timestamp_end!=0:
+    if timestamp_end==0:
         timestamp_end = timestamp_start
     jsonurl = '{0}={1}&upto={2}'.format(program_url,
                                         int(timestamp_start-tol*1e9),