diff --git a/ush/gfs_bufr.sh b/ush/gfs_bufr.sh
index c6703d16b9..1e8ad8cde0 100755
--- a/ush/gfs_bufr.sh
+++ b/ush/gfs_bufr.sh
@@ -19,7 +19,7 @@
 # 2019-10-10  Guang Ping Lou: Read in NetCDF files
 # echo "History: February 2003 - First implementation of this utility script"
 #
-source "${HOMEgfs:-?}/ush/preamble.sh"
+source "${HOMEgfs:?}/ush/preamble.sh"
 
 if [[ "${F00FLAG}" == "YES" ]]; then
    f00flag=".true."