diff --git a/Tools/completion/zsh/_ap_autotest b/Tools/completion/zsh/_ap_autotest
index a69e60a4b8..bed7e00df9 100644
--- a/Tools/completion/zsh/_ap_autotest
+++ b/Tools/completion/zsh/_ap_autotest
@@ -6,17 +6,16 @@ _ap_autotest() {
   local context state line curcontext="$curcontext"
   _arguments -C \
     '(- 1 *)'{-h,--help}'[show help options and exit]' \
-    ': :_ap_autotest_cmds' \
-    '*:: :->args' &&
-    ret=0
+    '(- 1 *)--list[list the available steps]' \
+    '(- 1 *)--list-subtests[list available subtests e.g. test.Copter]' \
+    ':first parameter:_ap_autotest_cmds' \
+    '*:: :->args'
+
   case "$state" in
     (args)
       _arguments -C \
         '--skip[list of steps to skip (comma separated)]' \
         '(-j --jobs)'{-j,--jobs}'[number of processors to use during build]:int:' \
-        '--skip[list of steps to skip (comma separated)]' \
-        '--list[list the available steps]' \
-        '--list-subtests[list available subtests e.g. test.Copter]' \
         '--viewerip[IP address to send MAVLink and fg packets to]:VIEWERIP:' \
         '--map[show map]' \
         '--experimental[enable experimental tests]' \
@@ -30,20 +29,60 @@ _ap_autotest() {
         '--debug[make built binaries debug binaries]' \
         '--speedup[speedup to run the simulations at]:SPEEDUP:' \
         '--valgrind[run ArduPilot binaries under valgrind]' \
-        '--gdb[run ArduPilot binaries under gdb]' \
+        '--gdb[run ArduPilot ot binaries under gdb]' \
         '--gdbserver[run ArduPilot binaries under gdbserver]' \
         '(-B --breakpoint)'{-B,--breakpoint}'[add a breakpoint at given location in debugger]:BREAKPOINT:' \
         '--disable-breakpoints[disable all breakpoints before starting]' \
         '*: :_ap_autotest_cmds' \
-        && ret=0
       ;;
     esac
 }
 
 (( $+functions[_ap_autotest_cmds] )) ||
   _ap_autotest_cmds() {
-    default_options=( $($caller --list))
-    _describe -t default-options 'default_options' default_options "$@" && ret=0
+  local suf
+  local tasks
+  # check we are on something like test.Copter
+  if compset -P '*[.]*[.]'; then
+    local type; type="$(echo ${words[$CURRENT]} | cut -d'.' -f1)"
+    local vehicle; vehicle="$(echo ${words[$CURRENT]} | cut -d'.' -f2)"
+    # check that we want completing test
+    case $type in
+    test)
+      tasks=( $($caller --list-subtests-for-vehicle $vehicle) )
+      suf=( -qS '.' )
+      _wanted "vehiclfdsfses" expl "vehifdsfcle" compadd $tasks && return 0
+      ;;
+    esac
+  else
+    # check we are on something like test.
+    if compset -P '*[.]'; then
+      local type; type="$(echo ${words[$CURRENT]} | cut -d'.' -f1)"
+      case $type in
+      test)
+        tasks=( $($caller --list-vehicles-test) )
+        # add dot after vehicle name for further completion
+        suf=( -qS '.' )
+        ;;
+      build)
+        # remove first and last line, get the lines starting with build, replace line return by space
+        tasks=( $($caller --list | sed -e '1d' -e '$d' | sed  -n 's/\bbuild\b.*\.//p' | tr '\n' ' ') )
+        # don't add more dot on non test
+        suf=( )
+        ;;
+      run)
+        # remove first and last line, get the lines starting with run, replace line return by space
+        tasks=( $($caller --list | sed -e '1d' -e '$d' | sed  -n 's/\brun\b.*\.//p' | tr '\n' ' ' ) )
+        # don't add more dot on non test
+        suf=( )
+        ;;
+      esac
+    else
+      tasks=(build test run)
+      suf=( -qS '.' )
+    fi
+    _wanted "schemes" expl "scheme" compadd $suf[@] $tasks && return 0
+  fi
   }
 
 # get the calling program, remove anything after the space == all commands arguments