diff --git a/src/error.rs b/src/error.rs
index 6c3a4f43..e9aecbf8 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -134,7 +134,7 @@ impl fmt::Display for Error {
             ErrorKind::Char {
                 character, index, ..
             } => {
-                write!(f, "invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-zA-Z], found `{}` at {}", character, index)
+                write!(f, "invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-fA-F-], found `{}` at {}", character, index)
             }
             ErrorKind::SimpleLength { len } => {
                 write!(
diff --git a/src/external/serde_support.rs b/src/external/serde_support.rs
index 9c1a7244..5228daf1 100644
--- a/src/external/serde_support.rs
+++ b/src/external/serde_support.rs
@@ -302,7 +302,7 @@ mod serde_tests {
     fn test_de_failure() {
         serde_test::assert_de_tokens_error::<Readable<Uuid>>(
             &[Token::Str("hello_world")],
-            "UUID parsing failed: invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-zA-Z], found `h` at 1",
+            "UUID parsing failed: invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-fA-F-], found `h` at 1",
         );
 
         serde_test::assert_de_tokens_error::<Compact<Uuid>>(
diff --git a/src/macros.rs b/src/macros.rs
index de200486..281c5335 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -72,7 +72,7 @@ define_uuid_macro! {
 /// Provides the following compilation error:
 ///
 /// ```txt
-/// error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found Z at 9
+/// error: invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-fA-F-], found Z at 9
 ///     |
 ///     |     let id = uuid!("F9168C5E-ZEB2-4FAA-B6BF-329BF39FA1E4");
 ///     |                              ^