diff --git a/README.md b/README.md
index f6b685b8..dd31e4ed 100644
--- a/README.md
+++ b/README.md
@@ -2825,11 +2825,10 @@ details. If you want to see which tag files YCM will read for a given buffer,
 run `:echo tagfiles()` with the relevant buffer active. Note that that function
 will only list tag files that already exist.
 
-### `CTRL-U` in insert mode does not work
+### `CTRL-U` in insert mode does not work while the completion menu is visible
 
-YCM keeps you in a `completefunc` completion mode when you're typing in insert
-mode and Vim disables `<C-U>` in completion mode as a "feature." Sadly there's
-nothing I can do about this.
+YCM uses `completefunc` completion mode to show suggestions and Vim disables
+`<C-U>` in that mode as a "feature." Sadly there's nothing I can do about this.
 
 ### YCM conflicts with UltiSnips TAB key usage
 
diff --git a/autoload/youcompleteme.vim b/autoload/youcompleteme.vim
index 823b134f..c813d386 100644
--- a/autoload/youcompleteme.vim
+++ b/autoload/youcompleteme.vim
@@ -546,14 +546,19 @@ function! s:SendKeys( keys )
 endfunction
 
 
-function! s:OnInsertChar()
-  call timer_stop( s:pollers.completion.id )
+function! s:CloseCompletionMenu()
   if pumvisible()
     call s:SendKeys( "\<C-e>" )
   endif
 endfunction
 
 
+function! s:OnInsertChar()
+  call timer_stop( s:pollers.completion.id )
+  call s:CloseCompletionMenu()
+endfunction
+
+
 function! s:OnDeleteChar( key )
   call timer_stop( s:pollers.completion.id )
   if pumvisible()
@@ -751,25 +756,26 @@ endfunction
 
 
 function! s:Complete()
-  " <c-x><c-u> invokes the user's completion function (which we have set to
-  " youcompleteme#CompleteFunc), and <c-p> tells Vim to select the previous
-  " completion candidate. This is necessary because by default, Vim selects the
-  " first candidate when completion is invoked, and selecting a candidate
-  " automatically replaces the current text with it. Calling <c-p> forces Vim to
-  " deselect the first candidate and in turn preserve the user's current text
-  " until he explicitly chooses to replace it with a completion.
-  call s:SendKeys( "\<C-X>\<C-U>\<C-P>" )
+  " Do not call user's completion function if the start column is after the
+  " current column or if there are no candidates. Close the completion menu
+  " instead. This avoids keeping the user in completion mode.
+  if s:completion.start_column > col( '.' ) || empty( s:completion.candidates )
+    call s:CloseCompletionMenu()
+  else
+    " <c-x><c-u> invokes the user's completion function (which we have set to
+    " youcompleteme#CompleteFunc), and <c-p> tells Vim to select the previous
+    " completion candidate. This is necessary because by default, Vim selects the
+    " first candidate when completion is invoked, and selecting a candidate
+    " automatically replaces the current text with it. Calling <c-p> forces Vim to
+    " deselect the first candidate and in turn preserve the user's current text
+    " until he explicitly chooses to replace it with a completion.
+    call s:SendKeys( "\<C-X>\<C-U>\<C-P>" )
+  endif
 endfunction
 
 
 function! youcompleteme#CompleteFunc( findstart, base )
   if a:findstart
-    if s:completion.start_column > col( '.' ) ||
-          \ empty( s:completion.candidates )
-      " For vim, -2 means not found but don't trigger an error message.
-      " See :h complete-functions.
-      return -2
-    endif
     return s:completion.start_column - 1
   endif
   return s:completion.candidates
diff --git a/doc/youcompleteme.txt b/doc/youcompleteme.txt
index 7f5895dc..0633fb58 100644
--- a/doc/youcompleteme.txt
+++ b/doc/youcompleteme.txt
@@ -148,7 +148,7 @@ Contents ~
   15. I get 'Fatal Python error: PyThreadState_Get: no current thread' on startup |youcompleteme-i-get-fatal-python-error-pythreadstate_get-no-current-thread-on-startup|
   16. 'install.py' says python must be compiled with '--enable-framework'. Wat? |youcompleteme-install.py-says-python-must-be-compiled-with-enable-framework-.-wat|
   17. YCM does not read identifiers from my tags files |youcompleteme-ycm-does-not-read-identifiers-from-my-tags-files|
-  18. 'CTRL-U' in insert mode does not work |youcompleteme-ctrl-u-in-insert-mode-does-not-work|
+  18. 'CTRL-U' in insert mode does not work while the completion menu is visible |youcompleteme-ctrl-u-in-insert-mode-does-not-work-while-completion-menu-is-visible|
   19. YCM conflicts with UltiSnips TAB key usage |youcompleteme-ycm-conflicts-with-ultisnips-tab-key-usage|
   20. Snippets added with ':UltiSnipsAddFiletypes' do not appear in the popup menu |youcompleteme-snippets-added-with-ultisnipsaddfiletypes-do-not-appear-in-popup-menu|
   21. Why isn't YCM just written in plain VimScript, FFS? |youcompleteme-why-isnt-ycm-just-written-in-plain-vimscript-ffs|
@@ -3087,12 +3087,11 @@ buffer, run ':echo tagfiles()' with the relevant buffer active. Note that that
 function will only list tag files that already exist.
 
 -------------------------------------------------------------------------------
-                            *youcompleteme-ctrl-u-in-insert-mode-does-not-work*
-'CTRL-U' in insert mode does not work ~
+*youcompleteme-ctrl-u-in-insert-mode-does-not-work-while-completion-menu-is-visible*
+'CTRL-U' in insert mode does not work while the completion menu is visible ~
 
-YCM keeps you in a 'completefunc' completion mode when you're typing in insert
-mode and Vim disables '<C-U>' in completion mode as a "feature." Sadly there's
-nothing I can do about this.
+YCM uses 'completefunc' completion mode to show suggestions and Vim disables
+'<C-U>' in that mode as a "feature." Sadly there's nothing I can do about this.
 
 -------------------------------------------------------------------------------
                      *youcompleteme-ycm-conflicts-with-ultisnips-tab-key-usage*