diff --git a/spec/completion_spec.lua b/spec/completion_spec.lua
index 0f5bdd9..ca39e7c 100644
--- a/spec/completion_spec.lua
+++ b/spec/completion_spec.lua
@@ -217,37 +217,84 @@ _comptest
 
    it("generates correct fish completion script", function()
       assert.equal([=[
+function __fish_comptest_print_command
+    set -l cmdline (commandline -poc)
+    set -l cmd
+    set -e cmdline[1]
+    for arg in $cmdline
+        switch $arg
+            case help
+                set cmd $cmd help
+                break
+            case completion
+                set cmd $cmd completion
+                break
+            case install i
+                set cmd $cmd install
+                break
+            case admin
+                set cmd $cmd admin
+                set -e cmdline[1]
+                for arg in $cmdline
+                    switch $arg
+                        case help
+                            set cmd $cmd help
+                            break
+                        case add
+                            set cmd $cmd add
+                            break
+                        case remove
+                            set cmd $cmd remove
+                            break
+                    end
+                end
+                break
+        end
+    end
+    echo "$cmd"
+end
 
-complete -c comptest -n '__fish_use_subcommand' -xa 'help' -d 'Show help for commands'
-complete -c comptest -n '__fish_use_subcommand' -xa 'completion' -d 'Output a shell completion script'
-complete -c comptest -n '__fish_use_subcommand' -xa 'install' -d 'Install a rock'
-complete -c comptest -n '__fish_use_subcommand' -xa 'i' -d 'Install a rock'
-complete -c comptest -n '__fish_use_subcommand' -xa 'admin' -d 'Rock server administration interface'
+function __fish_comptest_using_command
+    test (__fish_comptest_print_command) = "$argv"
+    and return 0
+    or return 1
+end
+
+function __fish_comptest_seen_command
+    string match -q "$argv*" (__fish_comptest_print_command)
+    and return 0
+    or return 1
+end
+
+complete -c comptest -n '__fish_comptest_using_command' -xa 'help' -d 'Show help for commands'
+complete -c comptest -n '__fish_comptest_using_command' -xa 'completion' -d 'Output a shell completion script'
+complete -c comptest -n '__fish_comptest_using_command' -xa 'install i' -d 'Install a rock'
+complete -c comptest -n '__fish_comptest_using_command' -xa 'admin' -d 'Rock server administration interface'
 complete -c comptest -s h -l help -d 'Show this help message and exit'
 complete -c comptest -l completion -xa 'bash zsh fish' -d 'Output a shell completion script for the specified shell'
 complete -c comptest -s v -l verbose -d 'Set the verbosity level'
 complete -c comptest -s f -l files -r -d 'A description with illegal "\' characters'
 
-complete -c comptest -n '__fish_seen_subcommand_from help' -xa 'help completion install i admin'
-complete -c comptest -n '__fish_seen_subcommand_from help' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_using_command help' -xa 'help completion install i admin'
+complete -c comptest -n '__fish_comptest_seen_command help' -s h -l help -d 'Show this help message and exit'
 
-complete -c comptest -n '__fish_seen_subcommand_from completion' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_seen_command completion' -s h -l help -d 'Show this help message and exit'
 
-complete -c comptest -n '__fish_seen_subcommand_from install i' -s h -l help -d 'Show this help message and exit'
-complete -c comptest -n '__fish_seen_subcommand_from install i' -l deps-mode -xa 'all one order none'
-complete -c comptest -n '__fish_seen_subcommand_from install i' -l no-doc -d 'Install without documentation'
+complete -c comptest -n '__fish_comptest_seen_command install' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_seen_command install' -l deps-mode -xa 'all one order none'
+complete -c comptest -n '__fish_comptest_seen_command install' -l no-doc -d 'Install without documentation'
 
-complete -c comptest -n '__fish_use_subcommand' -xa 'help' -d 'Show help for commands'
-complete -c comptest -n '__fish_use_subcommand' -xa 'add' -d 'Add a rock to a server'
-complete -c comptest -n '__fish_use_subcommand' -xa 'remove' -d 'Remove a rock from  a server'
-complete -c comptest -n '__fish_seen_subcommand_from admin' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_using_command admin' -xa 'help' -d 'Show help for commands'
+complete -c comptest -n '__fish_comptest_using_command admin' -xa 'add' -d 'Add a rock to a server'
+complete -c comptest -n '__fish_comptest_using_command admin' -xa 'remove' -d 'Remove a rock from  a server'
+complete -c comptest -n '__fish_comptest_seen_command admin' -s h -l help -d 'Show this help message and exit'
 
-complete -c comptest -n '__fish_seen_subcommand_from help' -xa 'help add remove'
-complete -c comptest -n '__fish_seen_subcommand_from help' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_using_command admin help' -xa 'help add remove'
+complete -c comptest -n '__fish_comptest_seen_command admin help' -s h -l help -d 'Show this help message and exit'
 
-complete -c comptest -n '__fish_seen_subcommand_from add' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_seen_command admin add' -s h -l help -d 'Show this help message and exit'
 
-complete -c comptest -n '__fish_seen_subcommand_from remove' -s h -l help -d 'Show this help message and exit'
+complete -c comptest -n '__fish_comptest_seen_command admin remove' -s h -l help -d 'Show this help message and exit'
 ]=], get_output("completion fish"))
    end)
 end)
diff --git a/src/argparse.lua b/src/argparse.lua
index a91da95..b17c746 100644
--- a/src/argparse.lua
+++ b/src/argparse.lua
@@ -584,12 +584,14 @@ function Option:_is_vararg()
    return self._maxargs ~= self._minargs
 end
 
-function Parser:_get_fullname()
+function Parser:_get_fullname(exclude_root)
    local parent = self._parent
    local buf = {self._name}
 
    while parent do
-      table.insert(buf, 1, parent._name)
+      if not exclude_root or parent._parent then
+         table.insert(buf, 1, parent._name)
+      end
       parent = parent._parent
    end
 
@@ -1441,23 +1443,48 @@ local function fish_escape(string)
    return string:gsub("[\\']", "\\%0")
 end
 
-function Parser:_fish_complete_help(buf, prefix)
+function Parser:_fish_get_cmd(buf, indent)
+   if #self._commands == 0 then
+      return
+   end
+
+   table.insert(buf, (" "):rep(indent) .. "set -e cmdline[1]")
+   table.insert(buf, (" "):rep(indent) .. "for arg in $cmdline")
+   table.insert(buf, (" "):rep(indent + 4) .. "switch $arg")
+
+   for _, command in ipairs(self._commands) do
+      table.insert(buf, (" "):rep(indent + 8) .. "case " .. table.concat(command._aliases, " "))
+      table.insert(buf, (" "):rep(indent + 12) .. "set cmd $cmd " .. command._name)
+      command:_fish_get_cmd(buf, indent + 12)
+      table.insert(buf, (" "):rep(indent + 12) .. "break")
+   end
+
+   table.insert(buf, (" "):rep(indent + 4) .. "end")
+   table.insert(buf, (" "):rep(indent) .. "end")
+end
+
+function Parser:_fish_complete_help(buf, basename)
+   local prefix = "complete -c " .. basename
    table.insert(buf, "")
 
    for _, command in ipairs(self._commands) do
-      for _, alias in ipairs(command._aliases) do
-         local line = ("%s -n '__fish_use_subcommand' -xa '%s'"):format(prefix, alias)
-         if command._description then
-            line = ("%s -d '%s'"):format(line, fish_escape(get_short_description(command)))
-         end
-         table.insert(buf, line)
+      local aliases = table.concat(command._aliases, " ")
+      local line
+      if self._parent then
+         line = ("%s -n '__fish_%s_using_command %s' -xa '%s'")
+            :format(prefix, basename, self:_get_fullname(true), aliases)
+      else
+         line = ("%s -n '__fish_%s_using_command' -xa '%s'"):format(prefix, basename, aliases)
       end
-
+      if command._description then
+         line = ("%s -d '%s'"):format(line, fish_escape(get_short_description(command)))
+      end
+      table.insert(buf, line)
    end
 
    if self._is_help_command then
-      local line = ("%s -n '__fish_seen_subcommand_from %s' -xa '%s'")
-         :format(prefix, table.concat(self._aliases, " "), self._parent:_get_commands())
+      local line = ("%s -n '__fish_%s_using_command %s' -xa '%s'")
+         :format(prefix, basename, self:_get_fullname(true), self._parent:_get_commands())
       table.insert(buf, line)
    end
 
@@ -1465,7 +1492,7 @@ function Parser:_fish_complete_help(buf, prefix)
       local parts = {prefix}
 
       if self._parent then
-         table.insert(parts, "-n '__fish_seen_subcommand_from " .. table.concat(self._aliases, " ") .. "'")
+         table.insert(parts, "-n '__fish_" .. basename .. "_seen_command " .. self:_get_fullname(true) .. "'")
       end
 
       for _, alias in ipairs(option._aliases) do
@@ -1490,7 +1517,7 @@ function Parser:_fish_complete_help(buf, prefix)
    end
 
    for _, command in ipairs(self._commands) do
-      command:_fish_complete_help(buf, prefix)
+      command:_fish_complete_help(buf, basename)
    end
 end
 
@@ -1498,8 +1525,31 @@ function Parser:get_fish_complete()
    self._basename = base_name(self._name)
    assert(self:_is_shell_safe())
    local buf = {}
-   local prefix = "complete -c " .. self._basename
-   self:_fish_complete_help(buf, prefix)
+
+   if #self._commands > 0 then
+      table.insert(buf, ([[
+function __fish_%s_print_command
+    set -l cmdline (commandline -poc)
+    set -l cmd]]):format(self._basename))
+      self:_fish_get_cmd(buf, 4)
+      table.insert(buf, ([[
+    echo "$cmd"
+end
+
+function __fish_%s_using_command
+    test (__fish_%s_print_command) = "$argv"
+    and return 0
+    or return 1
+end
+
+function __fish_%s_seen_command
+    string match -q "$argv*" (__fish_%s_print_command)
+    and return 0
+    or return 1
+end]]):format(self._basename, self._basename, self._basename, self._basename))
+   end
+
+   self:_fish_complete_help(buf, self._basename)
    return table.concat(buf, "\n") .. "\n"
 end