diff --git a/rowers/interactiveplots.py b/rowers/interactiveplots.py
index e063e701..ba3eba9e 100644
--- a/rowers/interactiveplots.py
+++ b/rowers/interactiveplots.py
@@ -2819,6 +2819,8 @@ def interactive_flex_chart2(id=0,promember=0,
     except KeyError:
         rowdata['power'] = 50.
 
+    # replace nans
+    rowdata.fillna(value=0,inplace=True)
         
     row = Workout.objects.get(id=id)
     if rowdata.empty: