diff --git a/vega/broadband_poly.py b/vega/broadband_poly.py
index 1762a6e..9af328a 100644
--- a/vega/broadband_poly.py
+++ b/vega/broadband_poly.py
@@ -76,9 +76,9 @@ def compute(self, params, pos_type):
                 raise ValueError(f'Broadband function {bb_term["func"]} not supported')
 
             if bb_poly_total is None:
-                bb_poly_total = 1 + bb_poly if 'mul' in pos_type else bb_poly
+                bb_poly_total = 1 + np.exp(bb_poly) if 'mul' in pos_type else bb_poly
             elif 'mul' in pos_type:
-                bb_poly_total *= 1 + bb_poly
+                bb_poly_total *= (1 + np.exp(bb_poly))
             else:
                 bb_poly_total += bb_poly