diff --git a/wetb/prepost/windIO.py b/wetb/prepost/windIO.py
index 1bf857909f2961923d5d1b854d43c71d84cadc34..6e87de7955cd97c6706f2b87fd12b51468c1721d 100755
--- a/wetb/prepost/windIO.py
+++ b/wetb/prepost/windIO.py
@@ -301,7 +301,7 @@ class LogFile(object):
             tempLog.append('')
 
         if iterations.shape == (0,3):
-            last_time_step = np.nan
+            last_time_step = 0
         else:
             last_time_step = iterations[time_step-1,0]