diff --git a/Cargo.lock b/Cargo.lock
index 4ebc494..e31ea95 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7,6 +7,7 @@ name = "alejandra"
 version = "3.0.0"
 dependencies = [
  "mimalloc",
+ "pretty_assertions",
  "rnix",
  "rowan",
 ]
@@ -112,6 +113,22 @@ version = "2.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "328b822bdcba4d4e402be8d9adb6eebf269f969f8eadef977a553ff3c4fbcb58"
 
+[[package]]
+name = "ctor"
+version = "0.1.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d2301688392eb071b0bf1a37be05c469d3cc4dbbd95df672fe28ab021e6a096"
+dependencies = [
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "diff"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
+
 [[package]]
 name = "futures"
 version = "0.3.25"
@@ -308,6 +325,15 @@ version = "6.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b5bf27447411e9ee3ff51186bf7a08e16c341efdde93f4d823e8844429bed7e"
 
+[[package]]
+name = "output_vt100"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "628223faebab4e3e40667ee0b2336d34a5b960ff60ea743ddfdbcf7770bcfb66"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.9"
@@ -320,6 +346,18 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
+[[package]]
+name = "pretty_assertions"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a25e9bcb20aa780fd0bb16b72403a9064d6b3f22f026946029acb941a50af755"
+dependencies = [
+ "ctor",
+ "diff",
+ "output_vt100",
+ "yansi",
+]
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -540,3 +578,9 @@ name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
+name = "yansi"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09041cd90cf85f7f8b2df60c646f853b7f535ce68f85244eb6731cf89fa498ec"
diff --git a/src/alejandra/Cargo.toml b/src/alejandra/Cargo.toml
index c00a132..4018e93 100644
--- a/src/alejandra/Cargo.toml
+++ b/src/alejandra/Cargo.toml
@@ -34,3 +34,6 @@ license = "Unlicense"
 name = "alejandra"
 repository = "https://github.com/kamadorueda/alejandra"
 version = "3.0.0"
+
+[dev-dependencies]
+pretty_assertions = "1.3.0"
diff --git a/src/alejandra/tests/fmt.rs b/src/alejandra/tests/fmt.rs
index b947c4e..d1fbbd8 100644
--- a/src/alejandra/tests/fmt.rs
+++ b/src/alejandra/tests/fmt.rs
@@ -1,3 +1,4 @@
+use pretty_assertions::assert_eq;
 use std::io::Write;
 
 #[test]
@@ -26,6 +27,6 @@ fn cases() {
 
         let content_out = std::fs::read_to_string(path_out.clone()).unwrap();
 
-        assert!(content_got == content_out);
+        assert_eq!(content_out, content_got, "Test case `{case}` failed; see `src/alejandra/tests/cases/{case}/`");
     }
 }