diff --git a/Cargo.lock b/Cargo.lock
index 2ea5d5d7..bc772f37 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -25,7 +25,6 @@ checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
 dependencies = [
  "crypto-common",
  "generic-array",
- "heapless",
 ]
 
 [[package]]
@@ -169,15 +168,6 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "atomic-polyfill"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cf2bce30dfe09ef0bfaef228b9d414faaf7e563035494d7fe092dba54b300f4"
-dependencies = [
- "critical-section",
-]
-
 [[package]]
 name = "autocfg"
 version = "1.5.1"
@@ -570,12 +560,6 @@ dependencies = [
  "itertools",
 ]
 
-[[package]]
-name = "critical-section"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "790eea4361631c5e7d22598ecd5723ff611904e3344ce8720784c93e3d83d40b"
-
 [[package]]
 name = "crossbeam-channel"
 version = "0.5.15"
@@ -1107,15 +1091,6 @@ dependencies = [
  "zerocopy 0.8.50",
 ]
 
-[[package]]
-name = "hash32"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0c35f58762feb77d74ebe43bdbc3210f09be9fe6742234d573bacc26ed92b67"
-dependencies = [
- "byteorder",
-]
-
 [[package]]
 name = "hashbrown"
 version = "0.15.5"
@@ -1131,20 +1106,6 @@ version = "0.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
 
-[[package]]
-name = "heapless"
-version = "0.7.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdc6457c0eb62c71aac4bc17216026d8410337c4126773b9c5daba343f17964f"
-dependencies = [
- "atomic-polyfill",
- "hash32",
- "rustc_version",
- "serde",
- "spin",
- "stable_deref_trait",
-]
-
 [[package]]
 name = "heck"
 version = "0.5.0"
@@ -1741,7 +1702,6 @@ dependencies = [
  "cobs",
  "embedded-io 0.4.0",
  "embedded-io 0.6.1",
- "heapless",
  "serde",
 ]
 
@@ -2407,21 +2367,6 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
-[[package]]
-name = "spin"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
-dependencies = [
- "lock_api",
-]
-
-[[package]]
-name = "stable_deref_trait"
-version = "1.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
-
 [[package]]
 name = "stacker"
 version = "0.1.24"
diff --git a/Cargo.toml b/Cargo.toml
index 07aa973b..34793da7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -64,13 +64,12 @@ blake2 = "0.10.6"
 sha3 = "0.10.8"
 chacha20poly1305 = { version = "0.10.1", default-features = false, features = [
   "std",
-  "heapless",
 ] }
 zerocopy = { version = "0.7.35", features = ["derive"] }
 home = "0.5.12"
 derive_builder = "0.20.2"
 tokio = { version = "1.46", features = ["macros", "rt-multi-thread"] }
-postcard = { version = "1.1.1", features = ["alloc"] }
+postcard = { version = "1.1.1", default-features = false, features = ["alloc"] }
 libcrux-test-utils = { git = "https://github.com/cryspen/libcrux.git", rev = "0ab6d2dd9c1f" }
 hex-literal = { version = "1.1.0" }
 hex = { version = "0.4.3" }
diff --git a/deny.toml b/deny.toml
index 238f6a85..1fa661ab 100644
--- a/deny.toml
+++ b/deny.toml
@@ -24,7 +24,7 @@ feature-depth = 1
 [advisories]
 # A list of advisory IDs to ignore. Note that ignored advisories will still
 # output a note when they are encountered.
-ignore = ["RUSTSEC-2024-0436", "RUSTSEC-2023-0089"]
+ignore = ["RUSTSEC-2024-0436"]
 # If this is true, then cargo deny will use the git executable to fetch advisory database.
 # If this is false, then it uses a built-in git library.
 # Setting this to true can be helpful if you have special authentication requirements that cargo-deny does not support.
diff --git a/supply-chain/config.toml b/supply-chain/config.toml
index a0fc43f3..97774561 100644
--- a/supply-chain/config.toml
+++ b/supply-chain/config.toml
@@ -85,10 +85,6 @@ criteria = "safe-to-deploy"
 version = "0.6.6"
 criteria = "safe-to-deploy"
 
-[[exemptions.atomic-polyfill]]
-version = "1.0.3"
-criteria = "safe-to-deploy"
-
 [[exemptions.autocfg]]
 version = "1.5.1"
 criteria = "safe-to-deploy"
@@ -185,10 +181,6 @@ criteria = "safe-to-deploy"
 version = "0.5.1"
 criteria = "safe-to-run"
 
-[[exemptions.critical-section]]
-version = "1.2.0"
-criteria = "safe-to-deploy"
-
 [[exemptions.crossbeam-deque]]
 version = "0.8.6"
 criteria = "safe-to-run"
@@ -349,18 +341,10 @@ criteria = "safe-to-deploy"
 version = "2.7.1"
 criteria = "safe-to-run"
 
-[[exemptions.hash32]]
-version = "0.2.1"
-criteria = "safe-to-deploy"
-
 [[exemptions.hashbrown]]
 version = "0.15.2"
 criteria = "safe-to-deploy"
 
-[[exemptions.heapless]]
-version = "0.7.17"
-criteria = "safe-to-deploy"
-
 [[exemptions.hex-literal]]
 version = "1.1.0"
 criteria = "safe-to-deploy"
@@ -681,14 +665,6 @@ criteria = "safe-to-deploy"
 version = "0.6.4"
 criteria = "safe-to-deploy"
 
-[[exemptions.spin]]
-version = "0.9.8"
-criteria = "safe-to-deploy"
-
-[[exemptions.stable_deref_trait]]
-version = "1.2.1"
-criteria = "safe-to-deploy"
-
 [[exemptions.stacker]]
 version = "0.1.24"
 criteria = "safe-to-deploy"