diff --git a/share/completions/mv.fish b/share/completions/mv.fish
index 3b0138f16..24a116307 100644
--- a/share/completions/mv.fish
+++ b/share/completions/mv.fish
@@ -1,12 +1,62 @@
-complete -c mv -s b -l backup -d "Make backup of each existing destination file"
-complete -c mv -s f -l force -d "Do not prompt before overwriting"
-complete -c mv -s i -l interactive -d "Prompt before overwrite"
-complete -c mv -l reply -x -a "yes no query" -d "Answer for overwrite questions"
-complete -c mv -l strip-trailing-slashes -d "Remove trailing slashes from source"
-complete -c mv -s S -l suffix -r -d "Backup suffix"
-complete -c mv -l target-directory -d "Target directory" -x -a "(__fish_complete_directories (commandline -ct) 'Target directory')"
-complete -c mv -s u -l update -d "Do not overwrite newer files"
-complete -c mv -s v -l verbose -d "Verbose mode"
-complete -c mv -l help -d "Display help and exit"
-complete -c mv -l version -d "Display version and exit"
+set -l uname (uname -s)
 
+## GNU mv
+if mv --version >/dev/null 2>/dev/null
+    # --backup requires an argument, -b does not accept an argument
+    complete -c mv -l backup -r -d "Backup each existing destination file" \
+             -x -ka "none\t'Never make backups'
+                     off\t'Never make backups'
+                     numbered\t'Make numbered backups'
+                     t\t'Make numbered backups'
+                     existing\t'Numbered backups if any exist, else simple'
+                     nil\t'Numbered backups if any exist, else simple'
+                     simple\t'Make simple backups'
+                     never\t'Make simple backups'"
+    complete -c mv -s b -d "Backup each existing destination file"
+    complete -c mv -s f -l force -d "Don't prompt before overwriting"
+    complete -c mv -s i -l interactive -d "Prompt before overwriting"
+    complete -c mv -s n -l no-clobber -d "Don't overwrite existing files"
+    # --reply has been deprecated for over a decade, and now GNU mv does not accept this option.
+    # Better to use -f instead of --reply=yes.
+    #   complete -c mv -l reply -x -a "yes no query" -d "Answer for overwrite questions"
+    complete -c mv -l strip-trailing-slashes -d "Remove trailing slashes from source args"
+    complete -c mv -s S -l suffix -x -d "Override default backup suffix"
+    complete -c mv -s t -l target-directory -d "Move all source args into DIRECTORY" \
+             -x -a "(__fish_complete_directories (commandline -ct) 'DIRECTORY')"
+    complete -c mv -s T -l no-target-directory -d "Treat DEST as a normal file"
+    complete -c mv -s u -l update -d "Don't overwrite newer files"
+    complete -c mv -s v -l verbose -d "Print each file as it is moved"
+    test "$uname" = Linux
+        and complete -c mv -s Z -l context -d "Sets SELinux context to default"
+
+    complete -c mv -l help -d "Print help and exit"
+    complete -c mv -l version -d "Print version and exit"
+## BSD-ish mv
+else             #[posix][ext]
+    # freebsd:   mv [-fi][nvh] src dst
+    # dragonfly: mv [-fi][nvh] src dst
+    # macos:     mv [-fi][nv ] src dst
+    # netbsd:    mv [-fi][ v ] src dst
+    # openbsd:   mv [-fi][ v ] src dst
+    # solaris:   mv [-fi][   ] src dst
+
+    # POSIX options
+    complete -c mv -s f -d "Don't prompt before overwriting"
+    complete -c mv -s i -d "Prompt before overwriting existing files"
+
+    test uname = SunOS # -fi
+        and exit 0
+
+    # Extensions
+    complete -c mv -s v -d "Print each file as it is moved"
+
+    contains "$uname" NetBSD OpenBSD # -fiv
+        and exit 0
+
+    complete -c mv -s n -d "Don't overwrite existing files"
+
+    test "$uname" = Darwin # -fivn
+        and exit 0
+
+    complete -c mv -s h -d "If target is a link to a directory, don't follow it"
+end