diff --git a/Cargo.lock b/Cargo.lock
index 0812bbe..42f433a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -65,6 +65,7 @@ version = "0.2.0"
 dependencies = [
  "chinese-number",
  "siphasher",
+ "unicode-normalization",
  "ureq",
 ]
 
@@ -313,12 +314,36 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "tinyvec"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa5fdc3bce6191a1dbc8c02d5c8bffcf557bafa17c124c5264a458f1b0613fa"
+dependencies = [
+ "tinyvec_macros",
+]
+
+[[package]]
+name = "tinyvec_macros"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
+[[package]]
+name = "unicode-normalization"
+version = "0.1.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fd4f6878c9cb28d874b009da9e8d183b5abc80117c40bbd187a1fde336be6e8"
+dependencies = [
+ "tinyvec",
+]
+
 [[package]]
 name = "untrusted"
 version = "0.9.0"
diff --git a/Cargo.toml b/Cargo.toml
index ef60841..51a6290 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,10 +15,11 @@ keywords = ["unicode", "symbols"]
 default = ["numeral-systems", "styling"]
 numeral-systems = ["dep:chinese-number"]
 styling = []
-_test-unicode-conformance = ["ureq"]
+_test-unicode-conformance = ["ureq", "dep:unicode-normalization"]
 
 [dependencies]
 chinese-number = { version = "0.7.7", default-features = false, features = ["number-to-chinese"], optional = true }
+unicode-normalization = { version = "0.1.25", optional = true }
 
 [dev-dependencies]
 siphasher = "1.0.2"
diff --git a/src/lib.rs b/src/lib.rs
index 0ad21d7..8a91fbc 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -191,6 +191,17 @@ mod test {
         }
     }
 
+    /// Tests that all symbols use NFC, i.e., use precomposed codepoints when
+    /// possible.
+    #[cfg(feature = "_test-unicode-conformance")]
+    #[test]
+    fn symbols_are_nfc() {
+        assert!(
+            are_all_variants_valid(ROOT, unicode_normalization::is_nfc),
+            "symbols should use NFC (see list above)",
+        )
+    }
+
     /// https://www.unicode.org/reports/tr51/#def_text_presentation_selector.
     const TEXT_PRESENTATION_SELECTOR: char = '\u{FE0E}';
     /// https://www.unicode.org/reports/tr51/#def_emoji_presentation_selector.
diff --git a/src/modules/sym.txt b/src/modules/sym.txt
index 439ccf1..9557c20 100644
--- a/src/modules/sym.txt
+++ b/src/modules/sym.txt
@@ -751,13 +751,13 @@ note
   .up 🎜
   .down 🎝
   .whole 𝅝
-  .half 𝅗𝅥
-  .quarter 𝅘𝅥
+  .half 𝅗𝅥
+  .quarter 𝅘𝅥
   .quarter.alt ♩
-  .eighth 𝅘𝅥𝅮
+  .eighth 𝅘𝅥𝅮
   .eighth.alt ♪
   .eighth.beamed ♫
-  .sixteenth 𝅘𝅥𝅯
+  .sixteenth 𝅘𝅥𝅯
   .sixteenth.beamed ♬
   .grace 𝆕
   .grace.slash 𝆔