diff --git a/src/parser.rs b/src/parser.rs
index b5759f2..1259a2c 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,47 +1,52 @@
 //! Module for converting XML custom token string to rust types.
 
-use std::num;
+pub(crate) use parse_prefixed_u32::ParsePrefixedU32;
+pub use parse_prefixed_u32::ParsePrefixedU32Error;
 
-use thiserror::Error;
+mod parse_prefixed_u32 {
+    use std::num;
 
-#[derive(Debug, Error)]
-pub enum ParsePrefixedU32Error {
-    #[error("invalid prefix: found {found}")]
-    InvalidPrefix { found: char },
-    #[error("parse int error")]
-    ParseIntError(#[from] num::ParseIntError),
-}
+    use thiserror::Error;
 
-pub(crate) trait ParsePrefixedU32 {
-    fn parse_prefixed_u32(&self) -> Result<u32, ParsePrefixedU32Error>;
-}
+    #[derive(Debug, Error)]
+    pub enum ParsePrefixedU32Error {
+        #[error("invalid prefix: found {found}")]
+        InvalidPrefix { found: char },
+        #[error("parse int error")]
+        ParseIntError(#[from] num::ParseIntError),
+    }
 
-impl ParsePrefixedU32 for &str {
-    fn parse_prefixed_u32(&self) -> Result<u32, ParsePrefixedU32Error> {
-        let radix = match self.chars().nth(1) {
-            Some('x') => 16,
-            Some(c) if c.is_numeric() => 10,
-            Some(c) => return Err(ParsePrefixedU32Error::InvalidPrefix { found: c }),
-            None => return Err(ParsePrefixedU32Error::InvalidPrefix { found: ' ' }),
-        };
+    pub(crate) trait ParsePrefixedU32 {
+        fn parse_prefixed_u32(&self) -> Result<u32, ParsePrefixedU32Error>;
+    }
 
-        match radix {
-            10 => Ok(self.parse()?),
-            radix => Ok(u32::from_str_radix(&self[2..], radix)?),
+    impl ParsePrefixedU32 for &str {
+        fn parse_prefixed_u32(&self) -> Result<u32, ParsePrefixedU32Error> {
+            let radix = match self.chars().nth(1) {
+                Some('x') => 16,
+                Some(c) if c.is_numeric() => 10,
+                Some(c) => return Err(ParsePrefixedU32Error::InvalidPrefix { found: c }),
+                None => return Err(ParsePrefixedU32Error::InvalidPrefix { found: ' ' }),
+            };
+
+            match radix {
+                10 => Ok(self.parse()?),
+                radix => Ok(u32::from_str_radix(&self[2..], radix)?),
+            }
+        }
+    }
+
+    #[cfg(test)]
+    mod test {
+        use super::ParsePrefixedU32;
+
+        #[test]
+        fn parse_prefixed_u32() {
+            assert_eq!("0xdeadbeef".parse_prefixed_u32().unwrap(), 0xdeadbeef);
+            assert_eq!("0xDEADBEEF".parse_prefixed_u32().unwrap(), 0xdeadbeef);
+            assert_eq!("1234".parse_prefixed_u32().unwrap(), 1234);
+
+            assert!("0abcde".parse_prefixed_u32().is_err());
         }
     }
 }
-
-#[cfg(test)]
-mod test {
-    use super::ParsePrefixedU32;
-
-    #[test]
-    fn parse_prefixed_u32() {
-        assert_eq!("0xdeadbeef".parse_prefixed_u32().unwrap(), 0xdeadbeef);
-        assert_eq!("0xDEADBEEF".parse_prefixed_u32().unwrap(), 0xdeadbeef);
-        assert_eq!("1234".parse_prefixed_u32().unwrap(), 1234);
-
-        assert!("0abcde".parse_prefixed_u32().is_err());
-    }
-}