diff --git a/zsh/commands b/zsh/commands
index d8c39b7..79c563f 100644
--- a/zsh/commands
+++ b/zsh/commands
@@ -32,19 +32,21 @@ whothefuckisusingport() {
 # functions
 
 function extract () {
-  if [ -f $1 ] ; then
-    case $1 in
-      *.tar.bz2)   tar xvjf $1    ;;
-      *.tar.gz)    tar xvzf $1    ;;
-      *.bz2)       bunzip2 $1     ;;
-      *.rar)       unrar x $1     ;;
-      *.gz)        gunzip $1      ;;
-      *.tar)       tar xvf $1     ;;
-      *.tbz2)      tar xvjf $1    ;;
-      *.tgz)       tar xvzf $1    ;;
-      *.zip)       unzip $1       ;;
-      *.Z)         uncompress $1  ;;
-      *.7z)        7z x $1        ;;
+  if [ -f "$1" ] ; then
+    case "$1" in
+      *.tar.bz2)   tar xvjf "$1"    ;;
+      *.tar.gz)    tar xvzf "$1"    ;;
+      *.bz2)       bunzip2 "$1"     ;;
+      *.rar)       unrar x "$1"     ;;
+      *.gz)        gunzip "$1"      ;;
+      *.tar)       tar xvf "$1"     ;;
+      *.tbz2)      tar xvjf "$1"    ;;
+      *.tgz)       tar xvzf "$1"    ;;
+      *.zip)       unzip "$1"       ;;
+      *.Z)         uncompress "$1"  ;;
+      *.7z)        7z x "$1"        ;;
+      *.xz)        unxz "$1"        ;;
+      *.zst)       zstd -d "$1"     ;;
       *)           echo "don't know how to extract '$1'..." ;;
     esac
   else