diff --git a/which.spec b/which.spec
index fac26a9..676c9a0 100644
--- a/which.spec
+++ b/which.spec
@@ -1,13 +1,14 @@
 Summary: Displays where a particular program in your path is located
 Name: which
 Version: 2.21
-Release: 24%{?dist}
+Release: 25%{?dist}
 License: GPLv3
 Source0: http://ftp.gnu.org/gnu/which/%{name}-%{version}.tar.gz
 Source1: which2.sh
 Source2: which2.csh
 Patch0: which-2.21-coverity-fixes.patch
 Url: https://savannah.gnu.org/projects/which/
+Requires: coreutils
 BuildRequires: make
 BuildRequires:  gcc
 BuildRequires: readline-devel
@@ -40,6 +41,9 @@ rm -f $RPM_BUILD_ROOT%{_infodir}/dir
 %{_mandir}/man1/which.1*
 
 %changelog
+* Mon Apr 26 2021 Than Ngo <than@redhat.com> - 2.21-25
+- improved which2.sh
+
 * Tue Mar 23 2021 Than Ngo <than@redhat.com> - 2.21-24
 - fixed regression if SHELL=zsh
 
diff --git a/which2.sh b/which2.sh
index 2b8b20a..16b930c 100644
--- a/which2.sh
+++ b/which2.sh
@@ -1,18 +1,18 @@
 # shellcheck shell=sh
 # Initialization script for bash, sh, mksh and ksh
 
-_declare="declare -f"
-_opt="-f"
-_shell="$(basename $SHELL)"
+which_declare="declare -f"
+which_opt="-f"
+which_shell="$(cat /proc/$$/comm)"
 
-if [ "$_shell" = "ksh" ] || [ "$_shell" = "mksh" ] || [ "$_shell" = "zsh" ] ; then
-  _declare="typeset -f"
-  _opt=""
+if [ "$which_shell" = "ksh" ] || [ "$which_shell" = "mksh" ] || [ "$which_shell" = "zsh" ] ; then
+  which_declare="typeset -f"
+  which_opt=""
 fi
  
 which ()
 {
-(alias; eval ${_declare}) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot "$@"
+(alias; eval ${which_declare}) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot "$@"
 }
 
-export ${_opt} which
+export ${which_opt} which