diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09f2eb0..74a88c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog].
   for [LaTeX](https://www.latex-project.org/), and
   [rustfmt](https://github.com/rust-lang/rustfmt) for
   [Rust](https://www.rust-lang.org/) ([#24]).
+* [Mix format](https://hexdocs.pm/mix/1.12/Mix.Tasks.Format.html) for Elixir
 
 ### Bugs fixed
 * Fix spelling error in generated process names ([#32]).
diff --git a/apheleia.el b/apheleia.el
index 0fcaf1c..0dd3720 100644
--- a/apheleia.el
+++ b/apheleia.el
@@ -461,6 +461,7 @@ modified from what is written to disk, then don't do anything."
   '((black . ("black" "-"))
     (brittany . ("brittany" file))
     (clang-format . ("clang-format" file))
+    (mix-format . ("mix" "format" "-"))
     (gofmt . ("gofmt"))
     (google-java-format . ("google-java-format" file))
     (latexindent . ("latexindent" file))
@@ -489,6 +490,7 @@ commands, lists of strings and symbols, in the format of
   '((cc-mode . clang-format)
     (c-mode . clang-format)
     (css-mode . prettier)
+    (elixir-mode . mix-format)
     (go-mode . gofmt)
     (haskell-mode . brittany)
     (html-mode . prettier)