diff --git a/src/builtin/meta.rs b/src/builtin/meta.rs
index 3bd8e5a..17fed3a 100644
--- a/src/builtin/meta.rs
+++ b/src/builtin/meta.rs
@@ -30,7 +30,7 @@ pub(crate) fn register(f: &mut HashMap<String, Builtin>) {
                 "extend-selector-pseudoclass" => Ok(Value::False),
                 // Full support for unit arithmetic using units defined in the
                 // [Values and Units Level 3][] spec.
-                "units-level-3" => Ok(Value::False),
+                "units-level-3" => Ok(Value::True),
                 // The Sass `@error` directive is supported.
                 "at-error" => Ok(Value::True),
                 // The "Custom Properties Level 1" spec is supported. This means
diff --git a/tests/meta.rs b/tests/meta.rs
index 4a98dc2..d5874ab 100644
--- a/tests/meta.rs
+++ b/tests/meta.rs
@@ -54,11 +54,11 @@ test!(
 //     "a {\n  color: feature-exists(extend-selector-pseudoclass)\n}\n",
 //     "a {\n  color: true;\n}\n"
 // );
-// test!(
-//     feature_exists_units_level_3,
-//     "a {\n  color: feature-exists(units-level-3)\n}\n",
-//     "a {\n  color: true;\n}\n"
-// );
+test!(
+    feature_exists_units_level_3,
+    "a {\n  color: feature-exists(units-level-3)\n}\n",
+    "a {\n  color: true;\n}\n"
+);
 // test!(
 //     feature_exists_custom_property,
 //     "a {\n  color: feature-exists(custom-property)\n}\n",