diff --git a/Cargo.lock b/Cargo.lock
index d1c9d66..df28362 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -314,9 +314,12 @@ checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
 
 [[package]]
 name = "convert_case"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb4a24b1aaf0fd0ce8b45161144d6f42cd91677fd5940fd431183eb023b3a2b8"
+checksum = "ec182b0ca2f35d8fc196cf3404988fd8b8c739a4d270ff118a398feb0cbec1ca"
+dependencies = [
+ "unicode-segmentation",
+]
 
 [[package]]
 name = "core-foundation"
@@ -1513,12 +1516,12 @@ dependencies = [
 name = "proc_macros"
 version = "0.0.1"
 dependencies = [
- "convert_case 0.5.0",
+ "convert_case 0.6.0",
  "json",
  "parse_duration",
  "proc-macro2",
  "quote",
- "syn 1.0.109",
+ "syn 2.0.10",
 ]
 
 [[package]]
@@ -2076,6 +2079,12 @@ dependencies = [
  "tinyvec",
 ]
 
+[[package]]
+name = "unicode-segmentation"
+version = "1.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1dd624098567895118886609431a7c3b8f516e41d30e0643f03d94592a147e36"
+
 [[package]]
 name = "unicode-width"
 version = "0.1.10"
diff --git a/proc_macros/Cargo.toml b/proc_macros/Cargo.toml
index 0abb673..737271a 100644
--- a/proc_macros/Cargo.toml
+++ b/proc_macros/Cargo.toml
@@ -16,4 +16,4 @@ json = "0"
 parse_duration = "2"
 proc-macro2 = "1"
 quote = "1"
-syn = { version = "1", features = ["full"] }
+syn = { version = "2", features = ["full"] }
diff --git a/proc_macros/proc_macros.rs b/proc_macros/proc_macros.rs
index b913e5f..4ce8ae7 100644
--- a/proc_macros/proc_macros.rs
+++ b/proc_macros/proc_macros.rs
@@ -238,7 +238,7 @@ impl Parse for HTTPHeader {
             if input.cursor().eof() {
                 break;
             }
-            match token::Sub::parse(input) {
+            match token::Minus::parse(input) {
                 Ok(_) => {}
                 Err(_) => {
                     break;
@@ -544,7 +544,7 @@ impl Parse for CheckJsonKeys {
             return Ok(Self { keys });
         }
         let first: LitStr = input.parse()?;
-        match input.parse::<token::Add>() {
+        match input.parse::<token::Plus>() {
             Ok(_) => match input.parse::<Ident>() {
                 Ok(ident) => {
                     keys.push((first, true, Some(ident), None));
@@ -571,7 +571,7 @@ impl Parse for CheckJsonKeys {
                 break;
             }
             let key: LitStr = input.parse()?;
-            match input.parse::<token::Add>() {
+            match input.parse::<token::Plus>() {
                 Ok(_) => match input.parse::<Ident>() {
                     Ok(ident) => {
                         keys.push((key, true, Some(ident), None));