diff --git a/examples/gen-axum/Cargo.lock b/examples/gen-axum/Cargo.lock
index f4b5499..37f005f 100644
--- a/examples/gen-axum/Cargo.lock
+++ b/examples/gen-axum/Cargo.lock
@@ -28,6 +28,18 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "ahash"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91429305e9f0a25f6205c5b8e0d2db09e0708a7a6df0f42212bb56c32c8ac97a"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "version_check",
+ "zerocopy",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.20"
@@ -114,7 +126,7 @@ checksum = "b9ccdd8f2a161be9bd5c023df56f1b2a0bd1d83872ae53b71a84a12c9bf6e842"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -535,7 +547,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "strsim",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -546,7 +558,7 @@ checksum = "29a358ff9f12ec09c3e61fef9b5a9902623a695a46a917b07f269bff1445611a"
 dependencies = [
  "darling_core",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -556,7 +568,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "907076dfda823b0b36d2a1bb5f90c96660a5bbcd7729e10727f07858f22c4edc"
 dependencies = [
  "cfg-if",
- "hashbrown",
+ "hashbrown 0.12.3",
  "lock_api",
  "once_cell",
  "parking_lot_core 0.9.6",
@@ -782,7 +794,7 @@ checksum = "89ca545a94061b6365f2c7355b4b32bd20df3ff95f02da9329b34ccc3bd6ee72"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -841,9 +853,9 @@ dependencies = [
  "http",
  "http-serde",
  "hyper",
- "metrics",
+ "metrics 0.20.1",
  "metrics-exporter-prometheus",
- "metrics-util",
+ "metrics-util 0.14.0",
  "mime",
  "num_cpus",
  "once_cell",
@@ -947,7 +959,16 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
 dependencies = [
- "ahash",
+ "ahash 0.7.6",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33ff8ae62cd3a9102e5637afc8452c55acf3844001bd5374e0b0bd7b6616c038"
+dependencies = [
+ "ahash 0.8.6",
 ]
 
 [[package]]
@@ -1182,7 +1203,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1885e79c1fc4b10f0e172c475f458b7f7b93061064d98c3293e98c5ba0c8b399"
 dependencies = [
  "autocfg",
- "hashbrown",
+ "hashbrown 0.12.3",
  "serde",
 ]
 
@@ -1309,6 +1330,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "mach2"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d0d1830bcd151a6fc4aea1369af235b36c1528fe976b8ff678683c9995eade8"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "matchers"
 version = "0.1.0"
@@ -1345,25 +1375,35 @@ version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b9b8653cec6897f73b519a43fba5ee3d50f62fe9af80b428accdcc093b4a849"
 dependencies = [
- "ahash",
- "metrics-macros",
- "portable-atomic",
+ "ahash 0.7.6",
+ "metrics-macros 0.6.0",
+ "portable-atomic 0.3.19",
+]
+
+[[package]]
+name = "metrics"
+version = "0.21.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fde3af1a009ed76a778cb84fdef9e7dbbdf5775ae3e4cc1f434a6a307f6f76c5"
+dependencies = [
+ "ahash 0.8.6",
+ "metrics-macros 0.7.0",
+ "portable-atomic 1.6.0",
 ]
 
 [[package]]
 name = "metrics-exporter-prometheus"
-version = "0.11.0"
+version = "0.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8603921e1f54ef386189335f288441af761e0fc61bcb552168d9cedfe63ebc70"
+checksum = "1d4fa7ce7c4862db464a37b0b31d89bca874562f034bd7993895572783d02950"
 dependencies = [
+ "base64 0.21.1",
  "hyper",
  "indexmap",
  "ipnet",
- "metrics",
- "metrics-util",
- "parking_lot 0.12.1",
- "portable-atomic",
- "quanta",
+ "metrics 0.21.1",
+ "metrics-util 0.15.1",
+ "quanta 0.11.1",
  "thiserror",
  "tokio",
  "tracing",
@@ -1380,6 +1420,17 @@ dependencies = [
  "syn 1.0.107",
 ]
 
+[[package]]
+name = "metrics-macros"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ddece26afd34c31585c74a4db0630c376df271c285d682d1e55012197830b6df"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.41",
+]
+
 [[package]]
 name = "metrics-util"
 version = "0.14.0"
@@ -1389,18 +1440,33 @@ dependencies = [
  "aho-corasick",
  "crossbeam-epoch",
  "crossbeam-utils",
- "hashbrown",
+ "hashbrown 0.12.3",
  "indexmap",
- "metrics",
+ "metrics 0.20.1",
  "num_cpus",
  "ordered-float",
  "parking_lot 0.12.1",
- "portable-atomic",
- "quanta",
+ "portable-atomic 0.3.19",
+ "quanta 0.10.1",
  "radix_trie",
  "sketches-ddsketch",
 ]
 
+[[package]]
+name = "metrics-util"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4de2ed6e491ed114b40b732e4d1659a9d53992ebd87490c44a6ffe23739d973e"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+ "hashbrown 0.13.1",
+ "metrics 0.21.1",
+ "num_cpus",
+ "quanta 0.11.1",
+ "sketches-ddsketch",
+]
+
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -1770,7 +1836,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccd746e37177e1711c20dd619a1620f34f5c8b569c53590a72dedd5344d8924a"
 dependencies = [
  "dlv-list",
- "hashbrown",
+ "hashbrown 0.12.3",
 ]
 
 [[package]]
@@ -1974,6 +2040,12 @@ version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26f6a7b87c2e435a3241addceeeff740ff8b7e76b74c13bf9acb17fa454ea00b"
 
+[[package]]
+name = "portable-atomic"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7170ef9988bc169ba16dd36a7fa041e5c4cbeb6a35b76d4c03daded371eae7c0"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.17"
@@ -2016,9 +2088,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.56"
+version = "1.0.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b63bdb0cd06f1f4dedf69b254734f9b45af66e4a031e42a7480257d9898b435"
+checksum = "39278fbbf5fb4f646ce651690877f89d1c5811a3d4acb27700c1cb3cdb78fd3b"
 dependencies = [
  "unicode-ident",
 ]
@@ -2094,11 +2166,27 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "quanta"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a17e662a7a8291a865152364c20c7abc5e60486ab2001e8ec10b24862de0b9ab"
+dependencies = [
+ "crossbeam-utils",
+ "libc",
+ "mach2",
+ "once_cell",
+ "raw-cpuid",
+ "wasi 0.11.0+wasi-snapshot-preview1",
+ "web-sys",
+ "winapi",
+]
+
 [[package]]
 name = "quote"
-version = "1.0.26"
+version = "1.0.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
 dependencies = [
  "proc-macro2",
 ]
@@ -2603,7 +2691,7 @@ checksum = "e801c1712f48475582b7696ac71e0ca34ebb30e09338425384269d9717c62cad"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -2674,7 +2762,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -2808,9 +2896,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.16"
+version = "2.0.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6f671d4b5ffdb8eadec19c0ae67fe2639df8684bd7bc4b83d986b8db549cf01"
+checksum = "44c8b28c477cc3bf0e7966561e3460130e1255f7a1cf71931075f1c5e7a7e269"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2887,7 +2975,7 @@ checksum = "f9456a42c5b0d803c8cd86e73dd7cc9edd429499f37a3550d286d5e86720569f"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
 ]
 
 [[package]]
@@ -3407,7 +3495,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn 2.0.16",
+ "syn 2.0.41",
  "uuid",
 ]
 
@@ -3763,6 +3851,26 @@ dependencies = [
  "linked-hash-map",
 ]
 
+[[package]]
+name = "zerocopy"
+version = "0.7.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1c4061bedbb353041c12f413700357bec76df2c7e2ca8e4df8bac24c6bf68e3d"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.7.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3c129550b3e6de3fd0ba67ba5c81818f9805e58b8d7fee80a3a59d2c9fc601a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.41",
+]
+
 [[package]]
 name = "zeroize"
 version = "1.5.7"
diff --git a/examples/gen-axum/Cargo.toml b/examples/gen-axum/Cargo.toml
index 8a4f1a4..f787897 100644
--- a/examples/gen-axum/Cargo.toml
+++ b/examples/gen-axum/Cargo.toml
@@ -47,7 +47,7 @@ http = "0.2"
 http-serde = "1.1"
 hyper = "0.14"
 metrics = "0.20"
-metrics-exporter-prometheus = "0.11"
+metrics-exporter-prometheus = "0.12"
 metrics-util = { version = "0.14", default-features = true }
 mime = "0.3"
 num_cpus = "1.0"