diff --git a/bin/git-forgit b/bin/git-forgit
index c45ab56..1b3b9de 100755
--- a/bin/git-forgit
+++ b/bin/git-forgit
@@ -314,10 +314,11 @@ _forgit_cherry_pick() {
     [[ $fzf_exitval != 0 ]] && return $fzf_exitval
     [[ -z "$fzf_selection" ]] && return $fzf_exitval
 
-    old_IFS=$IFS IFS=$'\n' 
+    ${IFS+"false"} && unset old_IFS || old_IFS="$IFS"
+    IFS=$'\n'
     # shellcheck disable=2207
     commits=($(echo "$fzf_selection" | sort --numeric-sort --key=1 | cut -f2 | cut -d' ' -f1 | _forgit_reverse_lines))
-    IFS=${old_IFS}
+    ${old_IFS+"false"} && unset IFS || IFS="$old_IFS"
     [ ${#commits[@]} -eq 0 ] && return 1
 
     $git_cherry_pick "${commits[@]}"
@@ -553,7 +554,8 @@ _forgit_revert_commit() {
     files=$(sed -nE 's/.* -- (.*)/\1/p' <<< "$*") # extract files parameters for `git show` command
     preview="echo {} | cut -f2- | $_forgit_extract_sha | xargs -I% git show --color=always % -- $files | $_forgit_show_pager"
 
-    old_IFS=$IFS IFS=$'\n' 
+    ${IFS+"false"} && unset old_IFS || old_IFS="$IFS"
+    IFS=$'\n'
     # shellcheck disable=2207
     commits=($(eval "$cmd" | 
         nl |
@@ -561,7 +563,7 @@ _forgit_revert_commit() {
         sort --numeric-sort --key=1 | 
         cut -f2- |
         sed 's/^[^a-f^0-9]*\([a-f0-9]*\).*/\1/'))
-    IFS=${old_IFS}
+    ${old_IFS+"false"} && unset IFS || IFS="$old_IFS"
 
     [ ${#commits[@]} -eq 0 ] && return 1
 
@@ -607,11 +609,12 @@ _forgit_ignore() {
         --preview=\"eval $cmd\"
         $FORGIT_IGNORE_FZF_OPTS
     "
-    old_IFS=$IFS IFS=$'\n' 
+    ${IFS+"false"} && unset old_IFS || old_IFS="$IFS"
+    IFS=$'\n'
     # shellcheck disable=SC2206,2207
     args=($@) && [[ $# -eq 0 ]] && args=($(_forgit_ignore_list | nl -nrn -w4 -s'  ' |
         FZF_DEFAULT_OPTS="$opts" fzf | awk '{print $2}'))
-    IFS=${old_IFS}
+    ${old_IFS+"false"} && unset IFS || IFS="$old_IFS"
     [ ${#args[@]} -eq 0 ] && return 1
     # shellcheck disable=SC2068
     _forgit_ignore_get ${args[@]}