diff --git a/Cargo.lock b/Cargo.lock
index 08a72b9c..8ea0205a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -79,9 +79,12 @@ checksum = "8da52d66c7071e2e3fa2a1e5c6d088fec47b593032b254f5e980de8ea54454d6"
 
 [[package]]
 name = "ascon"
-version = "0.3.1"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9fe9a0cff241855e9166670d259192aacf1e9a81b865dc9905afbbab31a9d2c1"
+checksum = "5f0e716048a18530cce4684daf98a7563a499d710e1ed8ef35567fcb43a7c5f1"
+dependencies = [
+ "zeroize",
+]
 
 [[package]]
 name = "ascon-aead"
@@ -554,27 +557,15 @@ checksum = "6bdef32e8150c2a081110b42772ffe7d7c9032b606bc226c8260fd97e0976601"
 
 [[package]]
 name = "syn"
-version = "1.0.109"
+version = "2.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+checksum = "79d9531f94112cfc3e4c8f5f02cb2b58f72c97b7efd85f70203cc6d8efda5927"
 dependencies = [
  "proc-macro2",
  "quote",
  "unicode-ident",
 ]
 
-[[package]]
-name = "synstructure"
-version = "0.12.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f36bdaa60a83aca3921b5259d5400cbf5e90fc51931376a9bd4a0eb79aa7210f"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
- "unicode-xid",
-]
-
 [[package]]
 name = "typenum"
 version = "1.16.0"
@@ -587,12 +578,6 @@ version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"
 
-[[package]]
-name = "unicode-xid"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
-
 [[package]]
 name = "universal-hash"
 version = "0.5.0"
@@ -637,12 +622,11 @@ dependencies = [
 
 [[package]]
 name = "zeroize_derive"
-version = "1.3.3"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "44bf07cb3e50ea2003396695d58bf46bc9887a1f362260446fad6bc4e79bd36c"
+checksum = "ce36e65b0d2999d2aafac989fb249189a141aee1f53c612c1f37d72631959f69"
 dependencies = [
  "proc-macro2",
  "quote",
  "syn",
- "synstructure",
 ]
diff --git a/ascon-aead/Cargo.toml b/ascon-aead/Cargo.toml
index 70b8eebd..4b8977a4 100644
--- a/ascon-aead/Cargo.toml
+++ b/ascon-aead/Cargo.toml
@@ -17,10 +17,10 @@ rust-version = "1.56"
 [dependencies]
 aead = { version = "0.5", default-features = false }
 subtle = { version = "2", default-features = false }
-zeroize = { version = "1.6", optional = true, default-features = false, features = [
+zeroize_crate = { package = "zeroize", version = "1.6", optional = true, default-features = false, features = [
     "derive",
 ] }
-ascon = "0.3"
+ascon = "0.4"
 
 [dev-dependencies]
 hex = "0.4"
@@ -28,7 +28,7 @@ aead = { version = "0.5", features = ["alloc"] }
 spectral = { version = "0.6", default-features = false }
 
 [features]
-default = ["alloc", "getrandom", "zeroize"]
+default = ["alloc", "getrandom"]
 std = ["aead/std", "alloc"]
 alloc = ["aead/alloc"]
 arrayvec = ["aead/arrayvec"]
@@ -36,6 +36,7 @@ getrandom = ["aead/getrandom", "rand_core"]
 heapless = ["aead/heapless"]
 rand_core = ["aead/rand_core"]
 stream = ["aead/stream"]
+zeroize = ["zeroize_crate", "ascon/zeroize"]
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/ascon-aead/src/lib.rs b/ascon-aead/src/lib.rs
index 43993411..81774e94 100644
--- a/ascon-aead/src/lib.rs
+++ b/ascon-aead/src/lib.rs
@@ -98,6 +98,9 @@
 //! Similarly, enabling the `arrayvec` feature of this crate will provide an impl of
 //! [`aead::Buffer`] for `arrayvec::ArrayVec`.
 
+#[cfg(feature = "zeroize")]
+extern crate zeroize_crate as zeroize;
+
 pub use aead::{self, Error, Key, Nonce, Tag};
 use aead::{
     consts::{U0, U16, U20},