diff --git a/tools/mksurfdata_esmf/gen_mksurfdata_namelist.py b/tools/mksurfdata_esmf/gen_mksurfdata_namelist.py
index af2e6b2c6e..d18e96f939 100755
--- a/tools/mksurfdata_esmf/gen_mksurfdata_namelist.py
+++ b/tools/mksurfdata_esmf/gen_mksurfdata_namelist.py
@@ -586,7 +586,7 @@ def main ():
  f'landuse.timeseries_{res}_{ssp_rcp_name}_{start_year}-{end_year}_{num_pft}_c{time_stamp}.nc'
 
     prefix = \
- f'surfdata_{res}_{ssp_rcp_name}_{start_year}_num_pft}pfts_c{time_stamp}.'
+ f'surfdata_{res}_{ssp_rcp_name}_{start_year}_{num_pft}pfts_c{time_stamp}.'
 
     nlfname = f'{prefix}namelist'
     fsurdat = f'{prefix}nc'