diff --git a/autoload/ale/engine.vim b/autoload/ale/engine.vim
index efd5dac..1ab9c8b 100644
--- a/autoload/ale/engine.vim
+++ b/autoload/ale/engine.vim
@@ -255,7 +255,7 @@ endfunction
 
 function! ale#engine#SetResults(buffer, loclist) abort
     if g:ale_set_quickfix || g:ale_set_loclist
-        call ale#list#SetLists(a:loclist)
+        call ale#list#SetLists(a:buffer, a:loclist)
     endif
 
     if g:ale_set_signs
diff --git a/autoload/ale/list.vim b/autoload/ale/list.vim
index a086b10..7b84676 100644
--- a/autoload/ale/list.vim
+++ b/autoload/ale/list.vim
@@ -11,11 +11,11 @@ function! ale#list#IsQuickfixOpen() abort
     return 0
 endfunction
 
-function! ale#list#SetLists(loclist) abort
+function! ale#list#SetLists(buffer, loclist) abort
     if g:ale_set_quickfix
         call setqflist(a:loclist)
     elseif g:ale_set_loclist
-        call setloclist(0, a:loclist)
+        call setloclist(bufwinid(str2nr(a:buffer)), a:loclist)
     endif
 
     " If we don't auto-open lists, bail out here.
diff --git a/plugin/ale.vim b/plugin/ale.vim
index bdbf3ad..8fa0093 100644
--- a/plugin/ale.vim
+++ b/plugin/ale.vim
@@ -194,7 +194,9 @@ function! s:ALEToggle() abort
         " Lint immediately
         call ale#Queue(0)
     else
-        for l:buffer in keys(g:ale_buffer_info)
+        " Make sure the buffer number is a number, not a string,
+        " otherwise things can go wrong.
+        for l:buffer in map(keys(g:ale_buffer_info), 'str2nr(v:val)')
             " Stop jobs and delete stored buffer data
             call ale#cleanup#Buffer(l:buffer)
             " Clear signs, loclist, quicklist
diff --git a/test/test_list_opening.vader b/test/test_list_opening.vader
index e3517bf..942f592 100644
--- a/test/test_list_opening.vader
+++ b/test/test_list_opening.vader
@@ -35,18 +35,18 @@ Execute(IsQuickfixOpen should return the right output):
   AssertEqual 0, ale#list#IsQuickfixOpen()
 
 Execute(The quickfix window should not open by default for the loclist):
-  call ale#list#SetLists(g:loclist)
+  call ale#list#SetLists(bufnr('%'), g:loclist)
   Assert !ale#list#IsQuickfixOpen()
 
 Execute(The quickfix window should open for just the loclist):
   let g:ale_open_list = 1
 
   " It should not open for an empty list.
-  call ale#list#SetLists([])
+  call ale#list#SetLists(bufnr('%'), [])
   Assert !ale#list#IsQuickfixOpen()
 
   " With a non-empty loclist, the window must open.
-  call ale#list#SetLists(g:loclist)
+  call ale#list#SetLists(bufnr('%'), g:loclist)
   Assert ale#list#IsQuickfixOpen()
 
 Execute(The quickfix window should stay open for just the loclist):
@@ -54,14 +54,14 @@ Execute(The quickfix window should stay open for just the loclist):
   let g:ale_keep_list_window_open = 1
 
   " The window should stay open after even after it is made blank again.
-  call ale#list#SetLists(g:loclist)
-  call ale#list#SetLists([])
+  call ale#list#SetLists(bufnr('%'), g:loclist)
+  call ale#list#SetLists(bufnr('%'), [])
   Assert ale#list#IsQuickfixOpen()
 
 Execute(The quickfix window should not open by default when quickfix is on):
   let g:ale_set_quickfix = 1
 
-  call ale#list#SetLists(g:loclist)
+  call ale#list#SetLists(bufnr('%'), g:loclist)
   Assert !ale#list#IsQuickfixOpen()
 
 Execute(The quickfix window should open for the quickfix list):
@@ -69,11 +69,11 @@ Execute(The quickfix window should open for the quickfix list):
   let g:ale_open_list = 1
 
   " It should not open for an empty list.
-  call ale#list#SetLists([])
+  call ale#list#SetLists(bufnr('%'), [])
   Assert !ale#list#IsQuickfixOpen()
 
   " With a non-empty quickfix list, the window must open.
-  call ale#list#SetLists(g:loclist)
+  call ale#list#SetLists(bufnr('%'), g:loclist)
   Assert ale#list#IsQuickfixOpen()
 
 Execute(The quickfix window should stay open for the quickfix list):
@@ -82,6 +82,6 @@ Execute(The quickfix window should stay open for the quickfix list):
   let g:ale_keep_list_window_open = 1
 
   " The window should stay open after even after it is made blank again.
-  call ale#list#SetLists(g:loclist)
-  call ale#list#SetLists([])
+  call ale#list#SetLists(bufnr('%'), g:loclist)
+  call ale#list#SetLists(bufnr('%'), [])
   Assert ale#list#IsQuickfixOpen()
diff --git a/test/test_setting_loclist_from_another_buffer.vader b/test/test_setting_loclist_from_another_buffer.vader
new file mode 100644
index 0000000..4b757c6
--- /dev/null
+++ b/test/test_setting_loclist_from_another_buffer.vader
@@ -0,0 +1,13 @@
+Before:
+  let g:original_buffer = bufnr('%')
+  new
+
+After:
+  unlet! g:original_buffer
+
+Execute(Errors should be set in the loclist for the original buffer, not the new one):
+  call ale#list#SetLists(g:original_buffer, [{'lnum': 4, 'text': 'foo'}])
+
+  AssertEqual [], getloclist(0)
+  AssertEqual 1, len(getloclist(bufwinid(g:original_buffer)))
+  AssertEqual 'foo', getloclist(bufwinid(g:original_buffer))[0].text