diff --git a/Cargo.lock b/Cargo.lock
index 76a7443..4a689d9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -22,7 +22,7 @@ dependencies = [
  "futures",
  "num_cpus",
  "rand",
- "serde_json",
+ "toml",
  "walkdir",
 ]
 
@@ -83,7 +83,7 @@ dependencies = [
  "bitflags",
  "clap_derive",
  "clap_lex",
- "indexmap",
+ "indexmap 1.9.3",
  "once_cell",
  "strsim",
  "termcolor",
@@ -124,6 +124,12 @@ version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
 
+[[package]]
+name = "equivalent"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
+
 [[package]]
 name = "futures"
 version = "0.3.31"
@@ -225,6 +231,12 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
 
+[[package]]
+name = "hashbrown"
+version = "0.15.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf151400ff0baff5465007dd2f3e717f3fe502074ca563069ce3a6629d07b289"
+
 [[package]]
 name = "heck"
 version = "0.4.1"
@@ -257,10 +269,14 @@ dependencies = [
 ]
 
 [[package]]
-name = "itoa"
-version = "1.0.13"
+name = "indexmap"
+version = "2.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "540654e97a3f4470a492cd30ff187bc95d89557a903a2bbf112e2fae98104ef2"
+checksum = "62f822373a4fe84d4bb149bf54e584a7f4abec90e072ed49cda0edea5b95471f"
+dependencies = [
+ "equivalent",
+ "hashbrown 0.15.2",
+]
 
 [[package]]
 name = "libc"
@@ -445,12 +461,6 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
-[[package]]
-name = "ryu"
-version = "1.0.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3cb5ba0dc43242ce17de99c180e96db90b235b8a9fdc9543c96d2209116bd9f"
-
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -481,14 +491,11 @@ dependencies = [
 ]
 
 [[package]]
-name = "serde_json"
-version = "1.0.133"
+name = "serde_spanned"
+version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7fceb2473b9166b2294ef05efcb65a3db80803f0b03ef86a5fc88a2b85ee377"
+checksum = "87607cb1398ed59d48732e575a4c28a7a8ebf2454b964fe3f224f2afc07909e1"
 dependencies = [
- "itoa",
- "memchr",
- "ryu",
  "serde",
 ]
 
@@ -565,6 +572,40 @@ version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23d434d3f8967a09480fb04132ebe0a3e088c173e6d0ee7897abbdf4eab0f8b9"
 
+[[package]]
+name = "toml"
+version = "0.8.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1ed1f98e3fdc28d6d910e6737ae6ab1a93bf1985935a1193e68f93eeb68d24e"
+dependencies = [
+ "serde",
+ "serde_spanned",
+ "toml_datetime",
+ "toml_edit",
+]
+
+[[package]]
+name = "toml_datetime"
+version = "0.6.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0dd7358ecb8fc2f8d014bf86f6f638ce72ba252a2c3a2572f2a795f1d23efb41"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "toml_edit"
+version = "0.22.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ae48d6208a266e853d946088ed816055e556cc6028c5e8e2b84d9fa5dd7c7f5"
+dependencies = [
+ "indexmap 2.7.0",
+ "serde",
+ "serde_spanned",
+ "toml_datetime",
+ "winnow",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.13"
@@ -697,6 +738,15 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
+[[package]]
+name = "winnow"
+version = "0.6.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36c1fec1a2bb5866f07c25f68c26e565c4c200aebb96d7e55710c19d3e8ac49b"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "yansi"
 version = "1.0.1"
diff --git a/src/alejandra/src/config.rs b/src/alejandra/src/config.rs
index 3fd03ed..359a64b 100644
--- a/src/alejandra/src/config.rs
+++ b/src/alejandra/src/config.rs
@@ -2,8 +2,10 @@ use serde::Deserialize;
 
 /// Configuration used by the formatter
 #[derive(Clone, Copy, Default, Deserialize)]
+#[serde(deny_unknown_fields)]
 pub struct Config {
     /// Indentation to use
+    #[serde(default)]
     pub indentation: Indentation,
 }
 
diff --git a/src/alejandra_cli/Cargo.toml b/src/alejandra_cli/Cargo.toml
index 6ff6d4c..e683fd6 100644
--- a/src/alejandra_cli/Cargo.toml
+++ b/src/alejandra_cli/Cargo.toml
@@ -19,7 +19,7 @@ rand = { version = "*", default-features = false, features = [
   "alloc",
   "getrandom",
 ] }
-serde_json = { version = "*", default-features = false, features = ["std"] }
+toml = { version = "*", default-features = false, features = ["parse"] }
 walkdir = { version = "*", default-features = false, features = [] }
 
 [package]
diff --git a/src/alejandra_cli/src/cli.rs b/src/alejandra_cli/src/cli.rs
index 26727de..040a0a0 100644
--- a/src/alejandra_cli/src/cli.rs
+++ b/src/alejandra_cli/src/cli.rs
@@ -40,7 +40,9 @@ struct CLIArgs {
     #[clap(long, short)]
     check: bool,
 
-    /// [Experimental] Path to a config file.
+    /// [Experimental] Path to a config file. If not provided, it'll default to
+    /// `alejandra.toml` in the current directory. If not found, it'll use the
+    /// default style.
     #[clap(long)]
     experimental_config: Option<String>,
 
@@ -238,6 +240,15 @@ pub fn main() -> ! {
 }
 
 fn resolve_config(path: Option<&str>, verbosity: Verbosity) -> Config {
+    let default_config_path = "alejandra.toml";
+
+    // If no path was provided and the default config path exists, use it
+    let path = path.or_else(|| {
+        std::fs::exists(default_config_path)
+            .unwrap_or(false)
+            .then_some(default_config_path)
+    });
+
     if let Some(path) = path {
         if verbosity.allows_info() {
             eprintln!("Using config from: {}", path);
@@ -250,7 +261,7 @@ fn resolve_config(path: Option<&str>, verbosity: Verbosity) -> Config {
             std::process::exit(1);
         });
 
-        serde_json::from_str::<Config>(&contents).unwrap_or_else(|error| {
+        toml::from_str::<Config>(&contents).unwrap_or_else(|error| {
             if verbosity.allows_errors() {
                 eprintln!("Errors found in config: {}", error);
             }