diff --git a/pyet/rad_utils.py b/pyet/rad_utils.py
index b10272f..610f151 100644
--- a/pyet/rad_utils.py
+++ b/pyet/rad_utils.py
@@ -199,7 +199,7 @@ def calc_rad_long(
     rso = rso.where(rso != 0, 0.001)
     if len(rs.shape) == 3 and len(rso.shape) == 1:
         rso = rso.values[:, newaxis, newaxis]
-    solar_rat = clip(rs / rso, 0.3, 1)
+    solar_rat = clip(rs.values / rso.values, 0.3, 1)
     if tmax is not None:
         tmp1 = STEFAN_BOLTZMANN_DAY * ((tmax + 273.16) ** 4 + (tmin + 273.16) ** 4) / 2
     else: