diff --git a/ale_linters/elixir/mix.vim b/ale_linters/elixir/mix.vim
index 948c6d3648..76380ef357 100644
--- a/ale_linters/elixir/mix.vim
+++ b/ale_linters/elixir/mix.vim
@@ -1,45 +1,88 @@
 " Author: evnu - https://github.com/evnu
 " Author: colbydehart - https://github.com/colbydehart
+" Author: toupeira - https://github.com/toupeira
 " Description: Mix compile checking for Elixir files
 
 function! ale_linters#elixir#mix#Handle(buffer, lines) abort
-    " Matches patterns like the following:
+    " Example output from Elixir 1.20.0:
     "
-    " Error format
-    " ** (CompileError) apps/sim/lib/sim/server.ex:87: undefined function update_in/4
+    "     warning: variable "a" is unused (if the variable is not meant to be used, prefix it with an underscore)
+    "     │
+    "  16 │     a = missing_var
+    "     │     ~
+    "     │
+    "     └─ lib/foo.ex:16:5: Foo.hello/0
     "
-    " TODO: Warning format
-    " warning: variable "foobar" does not exist and is being expanded to "foobar()", please use parentheses to remove the ambiguity or change the variable name
-    let l:pattern = '\v\(([^\)]+Error)\) ([^:]+):([^:]+): (.+)$'
+    "     warning: variable "b" is unused (if the variable is not meant to be used, prefix it with an underscore)
+    "     │
+    "  17 │     b = another_missing_var
+    "     │     ~
+    "     │
+    "     └─ lib/foo.ex:17:5: Foo.hello/0
+    "
+    "     error: undefined variable "another_missing_var"
+    "     │
+    "  17 │     b = another_missing_var
+    "     │         ^^^^^^^^^^^^^^^^^^^
+    "     │
+    "     └─ lib/foo.ex:17:9: Foo.hello/0
+    "
+    "     error: undefined variable "missing_var"
+    "     │
+    "  16 │     a = missing_var
+    "     │         ^^^^^^^^^^^
+    "     │
+    "     └─ lib/foo.ex:16:9: Foo.hello/0
+    "
+    "
+    " == Compilation error in file lib/foo.ex ==
+    " ** (CompileError) lib/foo.ex: cannot compile module Foo (errors have been logged)
+    "
+    " NOTE: The line with the error class is not captured because it always
+    " seems to be either a `CompileError` or a `SyntaxError`, with a generic
+    " message.
+    "
+    let l:pattern_text = '\v^    (warning|error): (.+)$'
+    let l:pattern_file = '\v^    └─ ([^ :]+):([0-9]+):([0-9]+)?'
+
+    let l:match_texts = ale#util#GetMatches(a:lines, l:pattern_text)
+    let l:match_files = ale#util#GetMatches(a:lines, l:pattern_file)
+
     let l:output = []
+    let l:index = 0
+
+    " Always add the full output as detail
+    let l:detail = join(a:lines, "\n")
 
-    for l:match in ale#util#GetMatches(a:lines, l:pattern)
-        let l:type = 'E'
-        let l:text = l:match[4]
+    for l:match_text in l:match_texts
+        let l:type = toupper(l:match_text[1][0])
+        let l:match_file = get(l:match_files, l:index, [])
+
+        if !ale#path#IsBufferPath(a:buffer, get(l:match_file, 1))
+            continue
+        endif
 
         call add(l:output, {
         \   'bufnr': a:buffer,
-        \   'lnum': l:match[3] + 0,
-        \   'col': 0,
         \   'type': l:type,
-        \   'text': l:text,
+        \   'detail': l:detail,
+        \   'text': get(l:match_text, 2, v:null),
+        \   'lnum': str2nr(get(l:match_file, 2, v:null)),
+        \   'col': str2nr(get(l:match_file, 3, v:null)),
         \})
+
+        let l:index += 1
     endfor
 
     return l:output
 endfunction
 
-function! ale_linters#elixir#mix#GetCommand(buffer) abort
-    let l:temp_dir = ale#command#CreateDirectory(a:buffer)
-
-    return ale#Env('MIX_BUILD_PATH', l:temp_dir) . 'mix compile %s'
-endfunction
-
 call ale#linter#Define('elixir', {
 \   'name': 'mix',
 \   'executable': 'mix',
 \   'cwd': function('ale#handlers#elixir#FindMixProjectRoot'),
-\   'command': function('ale_linters#elixir#mix#GetCommand'),
+\   'command': '%e compile',
+\   'output_stream': 'stderr',
 \   'callback': 'ale_linters#elixir#mix#Handle',
 \   'lint_file': 1,
 \})
diff --git a/test/handler/test_mix_handler.vader b/test/handler/test_mix_handler.vader
index fc04f8f731..ba7e07d37d 100644
--- a/test/handler/test_mix_handler.vader
+++ b/test/handler/test_mix_handler.vader
@@ -1,20 +1,85 @@
 Before:
   runtime ale_linters/elixir/mix.vim
+  call ale#test#SetFilename('/testplugin/lib/foo.ex')
 
 After:
   call ale#linter#Reset()
 
 Execute(The mix handler should parse lines correctly):
+  let input_lines = [
+  \ '    warning: variable "a" is unused (if the variable is not meant to be used, prefix it with an underscore)',
+  \ '    │',
+  \ ' 16 │     a = missing_var',
+  \ '    │     ~',
+  \ '    │',
+  \ '    └─ /testplugin/lib/foo.ex:16:5: Foo.hello/0',
+  \ '',
+  \ '    warning: variable "b" is unused (if the variable is not meant to be used, prefix it with an underscore)',
+  \ '    │',
+  \ ' 17 │     b = another_missing_var',
+  \ '    │     ~',
+  \ '    │',
+  \ '    └─ /testplugin/lib/foo.ex:17:5: Foo.hello/0',
+  \ '',
+  \ '    error: undefined variable "another_missing_var"',
+  \ '    │',
+  \ ' 17 │     b = another_missing_var',
+  \ '    │         ^^^^^^^^^^^^^^^^^^^',
+  \ '    │',
+  \ '    └─ /testplugin/lib/foo.ex:17:9: Foo.hello/0',
+  \ '',
+  \ '    error: undefined variable "missing_var"',
+  \ '    │',
+  \ ' 16 │     a = missing_var',
+  \ '    │         ^^^^^^^^^^^',
+  \ '    │',
+  \ '    └─ /testplugin/lib/foo.ex:16:9: Foo.hello/0',
+  \ '',
+  \ '    error: undefined variable "unrelated_var"',
+  \ '    │',
+  \ ' 16 │     a = unrelated_var',
+  \ '    │         ^^^^^^^^^^^',
+  \ '    │',
+  \ '    └─ /testplugin/lib/unrelated.ex:16:9: Foo.hello/0',
+  \ '',
+  \ '',
+  \ '== Compilation error in file /testplugin/lib/foo.ex ==',
+  \ '** (CompileError) /testplugin/lib/foo.ex: cannot compile module Foo (errors have been logged)',
+  \ ]
+
   AssertEqual
   \ [
   \   {
-  \     'bufnr': 347,
-  \     'lnum': 87,
-  \     'col': 0,
-  \     'text': 'undefined function update_in/4',
+  \     'bufnr': bufnr(''),
+  \     'lnum': 16,
+  \     'col': 5,
+  \     'type': 'W',
+  \     'text': 'variable "a" is unused (if the variable is not meant to be used, prefix it with an underscore)',
+  \     'detail': join(input_lines, "\n"),
+  \   },
+  \   {
+  \     'bufnr': bufnr(''),
+  \     'lnum': 17,
+  \     'col': 5,
+  \     'type': 'W',
+  \     'text': 'variable "b" is unused (if the variable is not meant to be used, prefix it with an underscore)',
+  \     'detail': join(input_lines, "\n"),
+  \   },
+  \   {
+  \     'bufnr': bufnr(''),
+  \     'lnum': 17,
+  \     'col': 9,
+  \     'type': 'E',
+  \     'text': 'undefined variable "another_missing_var"',
+  \     'detail': join(input_lines, "\n"),
+  \   },
+  \   {
+  \     'bufnr': bufnr(''),
+  \     'lnum': 16,
+  \     'col': 9,
   \     'type': 'E',
+  \     'text': 'undefined variable "missing_var"',
+  \     'detail': join(input_lines, "\n"),
   \   },
   \ ],
-  \ ale_linters#elixir#mix#Handle(347, [
-  \   '** (CompileError) apps/sim/lib/sim/server.ex:87: undefined function update_in/4'
-  \ ])
+  \ ale_linters#elixir#mix#Handle(bufnr(''), input_lines)
diff --git a/test/linter/test_elixir_mix.vader b/test/linter/test_elixir_mix.vader
index a04bee552e..825f6436db 100644
--- a/test/linter/test_elixir_mix.vader
+++ b/test/linter/test_elixir_mix.vader
@@ -1,19 +1,16 @@
 Before:
   call ale#assert#SetUpLinterTest('elixir', 'mix')
   call ale#test#SetFilename('../test-files/elixir/mix_project/lib/app.ex')
-  let g:env_prefix = ale#Env('MIX_BUILD_PATH', 'TEMP_DIR')
 
 After:
-  unlet! g:env_prefix
-
   call ale#assert#TearDownLinterTest()
 
 Execute(The default mix command should be correct):
   AssertLinterCwd ale#path#Simplify(g:dir . '/../test-files/elixir/mix_project')
-  AssertLinter 'mix', g:env_prefix . 'mix compile %s'
+  AssertLinter 'mix', ale#Escape('mix') . ' compile'
 
 Execute(Build mix commands with an umbrella root):
   call ale#test#SetFilename('../test-files/elixir/umbrella_project/apps/mix_project/lib/app.ex')
 
   AssertLinterCwd ale#path#Simplify(g:dir . '/../test-files/elixir/umbrella_project')
-  AssertLinter 'mix', g:env_prefix . 'mix compile %s'
+  AssertLinter 'mix', ale#Escape('mix') . ' compile'