diff --git a/modules/util/util.py b/modules/util/util.py
index 5b5d8853349090921bc54e910bc0970d36e4e202..7c4c2d696f2d2c3b1fa7e5eb0fa1e583ae8ea550 100644
--- a/modules/util/util.py
+++ b/modules/util/util.py
@@ -80,7 +80,7 @@ def pressure_to_altitude(pres, temp, prof_pres, prof_temp, sfc_pres=None, sfc_te
temp_s = [temp] + temp_s[i_top:]
if sfc_pres is not None:
- if pres > sfc_pres: # incoming pressure below surface
+ if pres > sfc_pres: # incoming pressure below surface
return -1
prof_pres = np.array(pres_s)