diff --git a/components/isceobj/Util/Library/python/Poly2D.py b/components/isceobj/Util/Library/python/Poly2D.py
index 447bd35e7..e81b81126 100755
--- a/components/isceobj/Util/Library/python/Poly2D.py
+++ b/components/isceobj/Util/Library/python/Poly2D.py
@@ -377,7 +377,7 @@ def polyfit(self,xin,yin,zin,
 
         val, res, rank, eigs = np.linalg.lstsq(A,z, rcond=cond)
         if len(res)> 0:
-            print('Chi squared: %f'%(np.sqrt(res/(1.0*len(z)))))
+            print('Chi squared: %f'%(float(np.sqrt(res/(1.0*len(z))))))
         else:
             print('No chi squared value....')
             print('Try reducing rank of polynomial.')