diff --git a/pyvisgen/fits/writer.py b/pyvisgen/fits/writer.py
index 2eec5a8..a422a41 100644
--- a/pyvisgen/fits/writer.py
+++ b/pyvisgen/fits/writer.py
@@ -38,8 +38,8 @@ def create_vis_hdu(data, obs, layout="vlba", source_name="sim-source-0"):
     # wcs
     ra = obs.ra.cpu().numpy().item()
     dec = obs.dec.cpu().numpy().item()
-    freq = (obs.ref_frequency.cpu().numpy().item() * un.Hz).value
-    freq_d = (obs.bandwidths.cpu().numpy().item() * un.Hz).value
+    freq = obs.ref_frequency.cpu().numpy().item()
+    freq_d = obs.bandwidths.cpu().numpy().item()
 
     ws = wcs.WCS(naxis=7)
     ws.wcs.crpix = [1, 1, 1, 1, 1, 1, 1]