diff --git a/CHANGELOG.md b/CHANGELOG.md
index ff8a18bd..ae4bd582 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - **breaking:** The routes `/foo` and `/:key` are considered to overlap and
     will cause a panic when constructing the router. This might be fixed in the future.
 - **fixed:** Expand accepted content types for JSON requests ([#378])
+- **fixed:** Support deserializing `i128` and `u128` in `extract::Path`
 - **breaking:** The router's type is now always `Router` regardless of how many routes or
   middleware are applies ([#404])
 
diff --git a/src/extract/path/de.rs b/src/extract/path/de.rs
index 6b9e4640..3c944a38 100644
--- a/src/extract/path/de.rs
+++ b/src/extract/path/de.rs
@@ -99,10 +99,12 @@ impl<'de> Deserializer<'de> for PathDeserializer<'de> {
     parse_single_value!(deserialize_i16, visit_i16, "i16");
     parse_single_value!(deserialize_i32, visit_i32, "i32");
     parse_single_value!(deserialize_i64, visit_i64, "i64");
+    parse_single_value!(deserialize_i128, visit_i128, "i128");
     parse_single_value!(deserialize_u8, visit_u8, "u8");
     parse_single_value!(deserialize_u16, visit_u16, "u16");
     parse_single_value!(deserialize_u32, visit_u32, "u32");
     parse_single_value!(deserialize_u64, visit_u64, "u64");
+    parse_single_value!(deserialize_u128, visit_u128, "u128");
     parse_single_value!(deserialize_f32, visit_f32, "f32");
     parse_single_value!(deserialize_f64, visit_f64, "f64");
     parse_single_value!(deserialize_string, visit_string, "String");
@@ -310,7 +312,7 @@ impl<'de> Deserializer<'de> for KeyDeserializer<'de> {
     }
 
     forward_to_deserialize_any! {
-        bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char bytes
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char bytes
         byte_buf option unit unit_struct seq tuple
         tuple_struct map newtype_struct struct enum ignored_any
     }
@@ -350,10 +352,12 @@ impl<'de> Deserializer<'de> for ValueDeserializer<'de> {
     parse_value!(deserialize_i16, visit_i16, "i16");
     parse_value!(deserialize_i32, visit_i32, "i16");
     parse_value!(deserialize_i64, visit_i64, "i64");
+    parse_value!(deserialize_i128, visit_i128, "i128");
     parse_value!(deserialize_u8, visit_u8, "u8");
     parse_value!(deserialize_u16, visit_u16, "u16");
     parse_value!(deserialize_u32, visit_u32, "u32");
     parse_value!(deserialize_u64, visit_u64, "u64");
+    parse_value!(deserialize_u128, visit_u128, "u128");
     parse_value!(deserialize_f32, visit_f32, "f32");
     parse_value!(deserialize_f64, visit_f64, "f64");
     parse_value!(deserialize_string, visit_string, "String");
@@ -591,10 +595,12 @@ mod tests {
         check_single_value!(i16, "-123", -123);
         check_single_value!(i32, "-123", -123);
         check_single_value!(i64, "-123", -123);
+        check_single_value!(i128, "123", 123);
         check_single_value!(u8, "123", 123);
         check_single_value!(u16, "123", 123);
         check_single_value!(u32, "123", 123);
         check_single_value!(u64, "123", 123);
+        check_single_value!(u128, "123", 123);
         check_single_value!(f32, "123", 123.0);
         check_single_value!(f64, "123", 123.0);
         check_single_value!(String, "abc", "abc");
diff --git a/src/extract/path/mod.rs b/src/extract/path/mod.rs
index 2fcefd4c..e74b977b 100644
--- a/src/extract/path/mod.rs
+++ b/src/extract/path/mod.rs
@@ -192,6 +192,27 @@ mod tests {
         assert_eq!(res.text().await, "one two");
     }
 
+    #[tokio::test]
+    async fn supports_128_bit_numbers() {
+        let app = Router::new()
+            .route(
+                "/i/:key",
+                get(|Path(param): Path<i128>| async move { param.to_string() }),
+            )
+            .route(
+                "/u/:key",
+                get(|Path(param): Path<u128>| async move { param.to_string() }),
+            );
+
+        let client = TestClient::new(app);
+
+        let res = client.get("/i/123").send().await;
+        assert_eq!(res.text().await, "123");
+
+        let res = client.get("/u/123").send().await;
+        assert_eq!(res.text().await, "123");
+    }
+
     #[tokio::test]
     async fn wildcard() {
         let app = Router::new()