diff --git a/Cargo.toml b/Cargo.toml
index bd1dfe9..fcc70f3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -69,7 +69,7 @@ phf_codegen = "0.13"
 
 [features]
 default = ["cli", "syntect-onig", "bon"]
-cli = ["clap", "bon", "shell-words", "xdg", "fmt2io", "shortcodes", "phoenix_heex", "attributes"]
+cli = ["clap", "bon", "shell-words", "xdg", "fmt2io", "shortcodes", "phoenix_heex", "attributes", "mimalloc"]
 shortcodes = ["emojis"]
 phoenix_heex = []
 attributes = []
@@ -107,6 +107,7 @@ clap = { version = "4", optional = true, features = [
     "string",
     "wrap_help",
 ] }
+mimalloc = { version = "0.1", optional = true }
 
 [[example]]
 name = "syntect"
diff --git a/src/main.rs b/src/main.rs
index 6c5b2a6..a439fb7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -10,6 +10,13 @@ use std::{boxed::Box, io::BufWriter};
 
 use clap::{Parser, ValueEnum};
 
+// The CLI churns many small AST allocations; mimalloc services them with
+// far fewer instructions than glibc malloc. Library consumers are
+// unaffected: this only applies to the comrak binary.
+#[cfg(not(target_arch = "wasm32"))]
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 use comrak::options;
 use comrak::{Arena, Options};
 #[cfg(feature = "syntect")]