diff --git a/python/loadleveller/jobstatus.py b/python/loadleveller/jobstatus.py
index 1f4039aadca9be9394c2abe675ae4a1a371e2a3b..bfbea0ee0af3fff1e8a2fc63c152cfc7ad0947ab 100644
--- a/python/loadleveller/jobstatus.py
+++ b/python/loadleveller/jobstatus.py
@@ -38,7 +38,7 @@ class JobProgress:
                     sweeps = f['/sweeps'][0]//jobfile.tasks[task].get('pt_sweeps_per_global_update',1)
                     
                     tp.therm_sweeps += min(sweeps,tp.target_therm)
-                    tp.sweeps += sweeps - tp.therm_sweeps
+                    tp.sweeps += max(0,sweeps - tp.target_therm)
 
 
             if tp.sweeps < tp.target_sweeps: