diff --git a/CHANGELOG.md b/CHANGELOG.md
index f0dc153..19b0bb0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 *   Improve processing of incoming `X-Spam-Flag` headers. Previously, in rare
     circumstances a message flagged as spam would not be rejected as requested.
     Reported by Petar Bogdanovic.
+*   Update dependencies.
 
 ## 0.1.5 (2021-03-16)
 
diff --git a/Cargo.lock b/Cargo.lock
index 07b446e..b657dd7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -83,9 +83,9 @@ checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
 
 [[package]]
 name = "milter"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e6730ab9bc9b2e61f4e3812c2e90df10b4a82ece5dcdb97dfa43f2958af1d65"
+checksum = "92e63d2a1125192952a422c891f6860ee48af6e256c07a48792d181e2752e20d"
 dependencies = [
  "bitflags",
  "libc",
@@ -96,9 +96,9 @@ dependencies = [
 
 [[package]]
 name = "milter-callback"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "efbf049f07ca24d03f1b677fac07d10fa56c99eafe3a5a9c24e54bbebe3a6ff8"
+checksum = "1bf7ad54ab8a2d8f324b5628140a585cfae22081d7bde7ebdc11bb7568e890ea"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -107,9 +107,9 @@ dependencies = [
 
 [[package]]
 name = "milter-sys"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b217e0b542739950688f2d7c98f3cb63823b5756c98e2b0cfe538b517e3c41b"
+checksum = "c6a5a6fe12debcf5428e77f5c0e569444a131c8c6043b1e2d1513680fa93cd25"
 dependencies = [
  "libc",
  "pkg-config",
@@ -184,9 +184,9 @@ checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
 [[package]]
 name = "syn"
-version = "1.0.70"
+version = "1.0.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9505f307c872bab8eb46f77ae357c8eba1fdacead58ee5a850116b1d7f82883"
+checksum = "ad184cc9470f9117b2ac6817bfe297307418819ba40552f9b3846f05c33d5373"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -221,9 +221,9 @@ checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
 [[package]]
 name = "vec_map"
diff --git a/Cargo.toml b/Cargo.toml
index 67e6716..1bdedba 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,5 +15,5 @@ chrono = "0.4.10"
 clap = "2.33"
 ipnet = "2.2"
 libc = "0.2.66"
-milter = "0.2.1"
+milter = "0.2.3"
 once_cell = "1.3"