diff --git a/autoload/SpaceVim/layers/denite.vim b/autoload/SpaceVim/layers/denite.vim
index 6965e904e..efdb86ead 100644
--- a/autoload/SpaceVim/layers/denite.vim
+++ b/autoload/SpaceVim/layers/denite.vim
@@ -24,6 +24,7 @@ endfunction
 let s:filename = expand('<sfile>:~')
 let s:lnum = expand('<slnum>') + 2
 function! SpaceVim#layers#denite#config() abort
+  call SpaceVim#mapping#space#def('nnoremap', ['?'], 'Denite menu:CustomKeyMaps -input=[SPC]', 'show mappings', 1)
   call SpaceVim#mapping#space#def('nnoremap', ['h', '[SPC]'], 'Denite help -input=SpaceVim', 'find-SpaceVim-help', 1)
   call SpaceVim#mapping#space#def('nnoremap', ['b', 'b'], 'Denite buffer', 'buffer list', 1)
   call SpaceVim#mapping#space#def('nnoremap', ['f', 'r'], 'Denite file_mru', 'open-recent-file', 1)
diff --git a/autoload/SpaceVim/layers/unite.vim b/autoload/SpaceVim/layers/unite.vim
index 9f565ee46..a135a2297 100644
--- a/autoload/SpaceVim/layers/unite.vim
+++ b/autoload/SpaceVim/layers/unite.vim
@@ -48,6 +48,7 @@ endfunction
 let s:filename = expand('<sfile>:~')
 let s:lnum = expand('<slnum>') + 2
 function! SpaceVim#layers#unite#config() abort
+  call SpaceVim#mapping#space#def('nnoremap', ['?'], 'Unite menu:CustomKeyMaps -input=[SPC]', 'show mappings', 1)
   call SpaceVim#mapping#space#def('nnoremap', ['h', '[SPC]'], 'Unite help -input=SpaceVim', 'unite-SpaceVim-help', 1)
   call SpaceVim#mapping#space#def('nnoremap', ['b', 'b'], 'Unite buffer', 'buffer list', 1)
   call SpaceVim#mapping#space#def('nnoremap', ['h', 'i'], 'UniteWithCursorWord help', 'get help with the symbol at point', 1)
diff --git a/autoload/SpaceVim/mapping/space.vim b/autoload/SpaceVim/mapping/space.vim
index 5e4632b5f..7939ac7d6 100644
--- a/autoload/SpaceVim/mapping/space.vim
+++ b/autoload/SpaceVim/mapping/space.vim
@@ -10,8 +10,6 @@ let s:file = expand('<sfile>:~')
 function! SpaceVim#mapping#space#init() abort
   let g:_spacevim_mappings_space = {}
   let g:_spacevim_mappings_prefixs['[SPC]'] = {'name' : '+SPC prefix'}
-  let g:_spacevim_mappings_space['?'] =
-        \ ['Unite menu:CustomKeyMaps -input=[SPC]', 'show mappings']
   let g:_spacevim_mappings_space.t = {'name' : '+Toggles'}
   let g:_spacevim_mappings_space.t.h = {'name' : '+Toggles highlight'}
   let g:_spacevim_mappings_space.t.m = {'name' : '+modeline'}
diff --git a/docs/documentation.md b/docs/documentation.md
index 302ff19b4..92912417f 100644
--- a/docs/documentation.md
+++ b/docs/documentation.md
@@ -766,18 +766,18 @@ features.
 
 But in current version of SpaceVim, leaderf/ctrlp and fzf layer has not be finished.
 
-| Feature             | unite   | denite  | leaderf | ctrlp   | fzf     |
-| ------------------- | ------- | ------- | ------- | ------- | ------- |
-| menu: CustomKeyMaps | **yes** | **yes** | no      | no      | no      |
-| register            | **yes** | **yes** | no      | **yes** | **yes** |
-| file                | **yes** | **yes** | **yes** | **yes** | **yes** |
-| yank history        | **yes** | **yes** | no      | no      | **yes** |
-| jump                | **yes** | **yes** | no      | **yes** | **yes** |
-| location list       | **yes** | **yes** | no      | no      | **yes** |
-| outline             | **yes** | **yes** | **yes** | **yes** | **yes** |
-| message             | **yes** | **yes** | no      | no      | **yes** |
-| quickfix list       | **yes** | **yes** | no      | **yes** | **yes** |
-| resume windows      | **yes** | **yes** | no      | no      | no      |
+| Feature            | unite | denite | leaderf | ctrlp | fzf |
+| ------------------ | ----- | ------ | ------- | ----- | --- |
+| menu CustomKeyMaps | yes   | yes    | no      | no    | no  |
+| register           | yes   | yes    | no      | yes   | yes |
+| file               | yes   | yes    | yes     | yes   | yes |
+| yank history       | yes   | yes    | no      | no    | yes |
+| jump               | yes   | yes    | no      | yes   | yes |
+| location list      | yes   | yes    | no      | no    | yes |
+| outline            | yes   | yes    | yes     | yes   | yes |
+| message            | yes   | yes    | no      | no    | yes |
+| quickfix list      | yes   | yes    | no      | yes   | yes |
+| resume windows     | yes   | yes    | no      | no    | no  |
 
 **Key bindings within fuzzy finder buffer**
 
diff --git a/wiki/en/Following-HEAD.md b/wiki/en/Following-HEAD.md
index 8ee6ab797..43f8f00f5 100644
--- a/wiki/en/Following-HEAD.md
+++ b/wiki/en/Following-HEAD.md
@@ -71,6 +71,7 @@ The next release is v0.9.0.
 - Fix icon in windows ([#2082](https://github.com/SpaceVim/SpaceVim/pull/2082))
 - Fix toggle highlight tail spaces ([#2080](https://github.com/SpaceVim/SpaceVim/pull/2080))
 - Fix lsp layer plugin installation ([#2108](https://github.com/SpaceVim/SpaceVim/pull/2108))
+- Fix key binding `SPC ?` ([#2109](https://github.com/SpaceVim/SpaceVim/pull/2109))
 
 ### Removed