diff --git a/rust/bssl-crypto/src/aead.rs b/rust/bssl-crypto/src/aead.rs
index 32579259a..d3677646b 100644
--- a/rust/bssl-crypto/src/aead.rs
+++ b/rust/bssl-crypto/src/aead.rs
@@ -31,11 +31,11 @@
 //! ```
 //! use bssl_crypto::aead::{Aead, Aes256Gcm};
 //!
-//! let key = [0u8; 32];
+//! let key = bssl_crypto::rand_array();
 //! let aead = Aes256Gcm::new(&key);
 //!
 //! let mut message_counter: u64 = 0;
-//! let mut nonce = [0u8; 12];
+//! let mut nonce = bssl_crypto::rand_array();
 //! nonce[4..].copy_from_slice(message_counter.to_be_bytes().as_slice());
 //! message_counter += 1;
 //! let plaintext = b"message";
diff --git a/rust/bssl-crypto/src/aes.rs b/rust/bssl-crypto/src/aes.rs
index 2527e8d2e..4602ee120 100644
--- a/rust/bssl-crypto/src/aes.rs
+++ b/rust/bssl-crypto/src/aes.rs
@@ -29,7 +29,7 @@
 //! ```
 //! use bssl_crypto::aes;
 //!
-//! let key_bytes = [0u8; 32];
+//! let key_bytes = bssl_crypto::rand_array();
 //! let enc_key = aes::EncryptKey::new_256(&key_bytes);
 //! let block = [0u8; aes::BLOCK_SIZE];
 //! let mut transformed_block = enc_key.encrypt(&block);
diff --git a/rust/bssl-crypto/src/hmac.rs b/rust/bssl-crypto/src/hmac.rs
index 2a07fbc23..bf482f760 100644
--- a/rust/bssl-crypto/src/hmac.rs
+++ b/rust/bssl-crypto/src/hmac.rs
@@ -30,7 +30,7 @@
 //! ```
 //! use bssl_crypto::hmac::HmacSha256;
 //!
-//! let key = [0u8; 32];
+//! let key = bssl_crypto::rand_array();
 //! let mut ctx = HmacSha256::new(&key);
 //! ctx.update(b"hel");
 //! ctx.update(b"lo");
@@ -46,7 +46,7 @@
 //! ```
 //! use bssl_crypto::hmac::HmacSha256;
 //!
-//! let key = [0u8; 32];
+//! let key = bssl_crypto::rand_array();
 //! let mut keyed_ctx = HmacSha256::new(&key);
 //! let mut ctx1 = keyed_ctx.clone();
 //! ctx1.update(b"foo");