diff --git a/Cargo.lock b/Cargo.lock
index 409113a..afb7e8c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -149,9 +149,9 @@ dependencies = [
 
 [[package]]
 name = "async-compression"
-version = "0.3.15"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "942c7cd7ae39e91bde4820d74132e9862e62c2f386c3aa90ccf55949f5bad63a"
+checksum = "5b0122885821398cc923ece939e24d1056a2384ee719432397fa9db87230ff11"
 dependencies = [
  "brotli",
  "futures-core",
@@ -4920,18 +4920,18 @@ checksum = "2a0956f1ba7c7909bfb66c2e9e4124ab6f6482560f6628b5aaeba39207c9aad9"
 
 [[package]]
 name = "zstd"
-version = "0.11.2+zstd.1.5.2"
+version = "0.12.3+zstd.1.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20cc960326ece64f010d2d2107537f26dc589a6573a316bd5b1dba685fa5fde4"
+checksum = "76eea132fb024e0e13fd9c2f5d5d595d8a967aa72382ac2f9d39fcc95afd0806"
 dependencies = [
  "zstd-safe",
 ]
 
 [[package]]
 name = "zstd-safe"
-version = "5.0.2+zstd.1.5.2"
+version = "6.0.5+zstd.1.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d2a5585e04f9eea4b2a3d1eca508c4dee9592a89ef6f450c11719da0726f4db"
+checksum = "d56d9e60b4b1758206c238a10165fbcae3ca37b01744e394c463463f6529d23b"
 dependencies = [
  "libc",
  "zstd-sys",
diff --git a/server/Cargo.toml b/server/Cargo.toml
index 0ef990d..d888395 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -62,7 +62,7 @@ console-subscriber = "0.1.9"
 xdg = "2.5.0"
 
 [dependencies.async-compression]
-version = "0.3.15"
+version = "0.4.0"
 features = [
 	"tokio",
 	"xz",
diff --git a/server/src/config.rs b/server/src/config.rs
index da7999f..7f24ba8 100644
--- a/server/src/config.rs
+++ b/server/src/config.rs
@@ -194,7 +194,7 @@ pub struct CompressionConfig {
     /// Compression level.
     ///
     /// If unspecified, Attic will choose a default one.
-    pub level: Option<u32>,
+    pub level: Option<i32>,
 }
 
 /// Compression type.