diff --git a/btk/draw_blends.py b/btk/draw_blends.py
index 42ddca6e8..5da0cb0fd 100644
--- a/btk/draw_blends.py
+++ b/btk/draw_blends.py
@@ -616,9 +616,10 @@ def render_single(self, entry, filt, psf, survey, extra_data):
         # get galaxy flux
         try:
             mag_name = f"{survey.name}_{filt.name}"
-            gal_flux = mag2counts(entry[mag_name], survey, filt).to_value("electron")
+            gal_mag = entry[mag_name]
         except KeyError:
-            gal_flux = mag2counts(entry["ref_mag"], survey, filt).to_value("electron")
+            gal_mag = entry["ref_mag"]
+        gal_flux = mag2counts(gal_mag, survey, filt).to_value("electron")
 
         gal = galsim_catalog.makeGalaxy(
             entry["btk_index"], gal_type=self.gal_type, noise_pad_size=0