diff --git a/Cargo.toml b/Cargo.toml
index 6a25c01..ea546f6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,6 +20,7 @@ otpauth = ["url", "urlencoding"]
 qr = ["qrcodegen", "image", "base64", "otpauth"]
 serde_support = ["serde"]
 gen_secret = ["rand"]
+zeroize = ["dep:zeroize"]
 
 [dependencies]
 serde = { version = "1.0", features = ["derive"], optional = true }
@@ -33,4 +34,5 @@ constant_time_eq = "~0.2.1"
 qrcodegen = { version = "~1.8", optional = true }
 image = { version = "~0.24.2", features = ["png"], optional = true, default-features = false}
 base64 = { version = "~0.13", optional = true }
-rand = { version = "~0.8.5", features = ["std_rng", "std"], optional = true, default-features = false }
\ No newline at end of file
+rand = { version = "~0.8.5", features = ["std_rng", "std"], optional = true, default-features = false }
+zeroize = { version = "1.5.7", features = ["alloc", "derive"], optional = true }
\ No newline at end of file
diff --git a/README.md b/README.md
index ec36ab6..7aea502 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,8 @@ With optional feature "otpauth", support parsing the TOTP parameters from an `ot
 With optional feature "serde_support", library-defined types `TOTP` and `Algorithm` and will be Deserialize-able and Serialize-able.
 ### gen_secret
 With optional feature "gen_secret", a secret will be generated for you to store in database.
+### zeroize
+Securely zero secret information when the TOTP struct is dropped.
 
 
 # Examples
diff --git a/examples/rfc-6238.rs b/examples/rfc-6238.rs
index 0dc9912..eefe4ed 100644
--- a/examples/rfc-6238.rs
+++ b/examples/rfc-6238.rs
@@ -2,7 +2,7 @@ use totp_rs::{Rfc6238, TOTP};
 
 #[cfg(feature = "otpauth")]
 fn main() {
-    let mut rfc = Rfc6238::with_defaults("totp-sercret-123").unwrap();
+    let mut rfc = Rfc6238::with_defaults("totp-sercret-123".as_bytes().to_vec()).unwrap();
 
     // optional, set digits, issuer, account_name
     rfc.digits(8).unwrap();
diff --git a/examples/ttl.rs b/examples/ttl.rs
index 3de5891..806f6c4 100644
--- a/examples/ttl.rs
+++ b/examples/ttl.rs
@@ -2,7 +2,7 @@ use totp_rs::{Algorithm, TOTP};
 
 #[cfg(not(feature = "otpauth"))]
 fn main() {
-    let totp = TOTP::new(Algorithm::SHA1, 6, 1, 30, "my-secret".to_string()).unwrap();
+    let totp = TOTP::new(Algorithm::SHA1, 6, 1, 30, "my-secret".as_bytes().to_vec()).unwrap();
 
     loop {
         println!(
@@ -22,7 +22,7 @@ fn main() {
         6,
         1,
         30,
-        "my-secret".to_string(),
+        "my-secret".as_bytes().to_vec(),
         Some("Github".to_string()),
         "constantoine@github.com".to_string(),
     )
diff --git a/src/lib.rs b/src/lib.rs
index 329002d..962cc81 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -36,7 +36,7 @@
 //!     6,
 //!     1,
 //!     30,
-//!     "supersecret_topsecret",
+//!     "supersecret_topsecret".as_bytes().to_vec(),
 //!     Some("Github".to_string()),
 //!     "constantoine@github.com".to_string(),
 //! ).unwrap();
@@ -126,8 +126,10 @@ fn system_time() -> Result<u64, SystemTimeError> {
 /// TOTP holds informations as to how to generate an auth code and validate it. Its [secret](struct.TOTP.html#structfield.secret) field is sensitive data, treat it accordingly
 #[derive(Debug, Clone)]
 #[cfg_attr(feature = "serde_support", derive(Serialize, Deserialize))]
-pub struct TOTP<T = Vec<u8>> {
+#[cfg_attr(feature = "zeroize", derive(zeroize::Zeroize, zeroize::ZeroizeOnDrop))]
+pub struct TOTP {
     /// SHA-1 is the most widespread algorithm used, and for totp pursposes, SHA-1 hash collisions are [not a problem](https://tools.ietf.org/html/rfc4226#appendix-B.2) as HMAC-SHA-1 is not impacted. It's also the main one cited in [rfc-6238](https://tools.ietf.org/html/rfc6238#section-3) even though the [reference implementation](https://tools.ietf.org/html/rfc6238#appendix-A) permits the use of SHA-1, SHA-256 and SHA-512. Not all clients support other algorithms then SHA-1
+    #[cfg_attr(feature = "zeroize", zeroize(skip))]
     pub algorithm: Algorithm,
     /// The number of digits composing the auth code. Per [rfc-4226](https://tools.ietf.org/html/rfc4226#section-5.3), this can oscilate between 6 and 8 digits
     pub digits: usize,
@@ -138,7 +140,7 @@ pub struct TOTP<T = Vec<u8>> {
     /// As per [rfc-4226](https://tools.ietf.org/html/rfc4226#section-4) the secret should come from a strong source, most likely a CSPRNG. It should be at least 128 bits, but 160 are recommended
     ///
     /// non-encoded value
-    pub secret: T,
+    pub secret: Vec<u8>,
     #[cfg(feature = "otpauth")]
     /// The "Github" part of "Github:constantoine@github.com". Must not contain a colon `:`
     /// For example, the name of your service/website.
@@ -150,7 +152,7 @@ pub struct TOTP<T = Vec<u8>> {
     pub account_name: String,
 }
 
-impl<T: AsRef<[u8]>> PartialEq for TOTP<T> {
+impl PartialEq for TOTP {
     /// Will not check for issuer and account_name equality
     /// As they aren't taken in account for token generation/token checking
     fn eq(&self, other: &Self) -> bool {
@@ -200,7 +202,7 @@ impl Default for TOTP {
     }
 }
 
-impl<T: AsRef<[u8]>> TOTP<T> {
+impl TOTP {
     #[cfg(feature = "otpauth")]
     /// Will create a new instance of TOTP with given parameters. See [the doc](struct.TOTP.html#fields) for reference as to how to choose those values
     ///
@@ -225,10 +227,10 @@ impl<T: AsRef<[u8]>> TOTP<T> {
         digits: usize,
         skew: u8,
         step: u64,
-        secret: T,
+        secret: Vec<u8>,
         issuer: Option<String>,
         account_name: String,
-    ) -> Result<TOTP<T>, TotpUrlError> {
+    ) -> Result<TOTP, TotpUrlError> {
         crate::rfc::assert_digits(&digits)?;
         crate::rfc::assert_secret_length(secret.as_ref())?;
         if issuer.is_some() && issuer.as_ref().unwrap().contains(':') {
@@ -288,7 +290,7 @@ impl<T: AsRef<[u8]>> TOTP<T> {
     /// # Errors
     ///
     /// Will return an error in case issuer or label contain the character ':'
-    pub fn from_rfc6238(rfc: Rfc6238<T>) -> Result<TOTP<T>, TotpUrlError> {
+    pub fn from_rfc6238(rfc: Rfc6238) -> Result<TOTP, TotpUrlError> {
         TOTP::try_from(rfc)
     }
 
@@ -369,7 +371,7 @@ impl<T: AsRef<[u8]>> TOTP<T> {
 
     /// Generate a TOTP from the standard otpauth URL
     #[cfg(feature = "otpauth")]
-    pub fn from_url<S: AsRef<str>>(url: S) -> Result<TOTP<Vec<u8>>, TotpUrlError> {
+    pub fn from_url<S: AsRef<str>>(url: S) -> Result<TOTP, TotpUrlError> {
         let url = Url::parse(url.as_ref()).map_err(TotpUrlError::Url)?;
         if url.scheme() != "otpauth" {
             return Err(TotpUrlError::Scheme(url.scheme().to_string()));
@@ -576,7 +578,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github:".to_string()),
             "constantoine@github.com".to_string(),
         );
@@ -592,7 +594,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine:github.com".to_string(),
         );
@@ -608,7 +610,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             None,
             "constantoine:github.com".to_string(),
         );
@@ -624,7 +626,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -634,7 +636,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -690,7 +692,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             None,
             "constantoine@github.com".to_string(),
         )
@@ -707,7 +709,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -724,7 +726,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -741,7 +743,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -767,7 +769,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -866,19 +868,19 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_err() {
-        assert!(TOTP::<Vec<u8>>::from_url("otpauth://hotp/123").is_err());
-        assert!(TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test").is_err());
-        assert!(TOTP::<Vec<u8>>::from_url(
+        assert!(TOTP::from_url("otpauth://hotp/123").is_err());
+        assert!(TOTP::from_url("otpauth://totp/GitHub:test").is_err());
+        assert!(TOTP::from_url(
             "otpauth://totp/GitHub:test:?secret=ABC&digits=8&period=60&algorithm=SHA256"
         )
         .is_err());
-        assert!(TOTP::<Vec<u8>>::from_url("otpauth://totp/Github:constantoine%40github.com?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=6&algorithm=SHA1").is_err())
+        assert!(TOTP::from_url("otpauth://totp/Github:constantoine%40github.com?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=6&algorithm=SHA1").is_err())
     }
 
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_default() {
-        let totp = TOTP::<Vec<u8>>::from_url(
+        let totp = TOTP::from_url(
             "otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ",
         )
         .unwrap();
@@ -899,7 +901,7 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_query() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256").unwrap();
+        let totp = TOTP::from_url("otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256").unwrap();
         assert_eq!(
             totp.secret,
             base32::decode(
@@ -917,7 +919,7 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_query_sha512() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA512").unwrap();
+        let totp = TOTP::from_url("otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA512").unwrap();
         assert_eq!(
             totp.secret,
             base32::decode(
@@ -935,13 +937,13 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_to_url() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/Github:constantoine%40github.com?issuer=Github&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=6&algorithm=SHA1").unwrap();
+        let totp = TOTP::from_url("otpauth://totp/Github:constantoine%40github.com?issuer=Github&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=6&algorithm=SHA1").unwrap();
         let totp_bis = TOTP::new(
             Algorithm::SHA1,
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -952,7 +954,7 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_unknown_param() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256&foo=bar").unwrap();
+        let totp = TOTP::from_url("otpauth://totp/GitHub:test?secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256&foo=bar").unwrap();
         assert_eq!(
             totp.secret,
             base32::decode(
@@ -970,25 +972,25 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_issuer_special() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/Github%40:constantoine%40github.com?issuer=Github%40&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=6&algorithm=SHA1").unwrap();
+        let totp = TOTP::from_url("otpauth://totp/Github%40:constantoine%40github.com?issuer=Github%40&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=6&algorithm=SHA1").unwrap();
         let totp_bis = TOTP::new(
             Algorithm::SHA1,
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github@".to_string()),
             "constantoine@github.com".to_string(),
         )
         .unwrap();
         assert_eq!(totp.get_url(), totp_bis.get_url());
-        assert_eq!(totp.issuer.unwrap(), "Github@");
+        assert_eq!(totp.issuer.as_ref().unwrap(), "Github@");
     }
 
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_query_issuer() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256").unwrap();
+        let totp = TOTP::from_url("otpauth://totp/GitHub:test?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256").unwrap();
         assert_eq!(
             totp.secret,
             base32::decode(
@@ -1001,13 +1003,13 @@ mod tests {
         assert_eq!(totp.digits, 8);
         assert_eq!(totp.skew, 1);
         assert_eq!(totp.step, 60);
-        assert_eq!(totp.issuer.unwrap(), "GitHub");
+        assert_eq!(totp.issuer.as_ref().unwrap(), "GitHub");
     }
 
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_wrong_scheme() {
-        let totp = TOTP::<Vec<u8>>::from_url("http://totp/GitHub:test?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256");
+        let totp = TOTP::from_url("http://totp/GitHub:test?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256");
         assert!(totp.is_err());
         let err = totp.unwrap_err();
         assert!(matches!(err, TotpUrlError::Scheme(_)));
@@ -1016,7 +1018,7 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_wrong_algo() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=MD5");
+        let totp = TOTP::from_url("otpauth://totp/GitHub:test?issuer=GitHub&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=MD5");
         assert!(totp.is_err());
         let err = totp.unwrap_err();
         assert!(matches!(err, TotpUrlError::Algorithm(_)));
@@ -1025,7 +1027,7 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn from_url_query_different_issuers() {
-        let totp = TOTP::<Vec<u8>>::from_url("otpauth://totp/GitHub:test?issuer=Gitlab&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256");
+        let totp = TOTP::from_url("otpauth://totp/GitHub:test?issuer=Gitlab&secret=KRSXG5CTMVRXEZLUKN2XAZLSKNSWG4TFOQ&digits=8&period=60&algorithm=SHA256");
         assert!(totp.is_err());
         assert!(matches!(
             totp.unwrap_err(),
@@ -1043,7 +1045,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
@@ -1069,7 +1071,7 @@ mod tests {
             6,
             1,
             1,
-            "TestSecretSuperSecret",
+            "TestSecretSuperSecret".as_bytes().to_vec(),
             Some("Github".to_string()),
             "constantoine@github.com".to_string(),
         )
diff --git a/src/rfc.rs b/src/rfc.rs
index 34204a7..988503d 100644
--- a/src/rfc.rs
+++ b/src/rfc.rs
@@ -54,7 +54,7 @@ pub fn assert_secret_length(secret: &[u8]) -> Result<(), Rfc6238Error> {
 /// use totp_rs::{Rfc6238, TOTP};
 ///
 /// let mut rfc = Rfc6238::with_defaults(
-///     "totp-sercret-123"
+///     "totp-sercret-123".as_bytes().to_vec()
 /// ).unwrap();
 ///
 /// // optional, set digits, issuer, account_name
@@ -64,7 +64,7 @@ pub fn assert_secret_length(secret: &[u8]) -> Result<(), Rfc6238Error> {
 /// ```
 #[derive(Debug, Clone)]
 #[cfg_attr(feature = "serde_support", derive(Serialize, Deserialize))]
-pub struct Rfc6238<T = Vec<u8>> {
+pub struct Rfc6238 {
     /// SHA-1
     algorithm: Algorithm,
     /// The number of digits composing the auth code. Per [rfc-4226](https://tools.ietf.org/html/rfc4226#section-5.3), this can oscilate between 6 and 8 digits
@@ -74,7 +74,7 @@ pub struct Rfc6238<T = Vec<u8>> {
     /// The recommended value per [rfc-6238](https://tools.ietf.org/html/rfc6238#section-5.2) is 30 seconds
     step: u64,
     /// As per [rfc-4226](https://tools.ietf.org/html/rfc4226#section-4) the secret should come from a strong source, most likely a CSPRNG. It should be at least 128 bits, but 160 are recommended
-    secret: T,
+    secret: Vec<u8>,
     #[cfg(feature = "otpauth")]
     /// The "Github" part of "Github:constantoine@github.com". Must not contain a colon `:`
     /// For example, the name of your service/website.
@@ -86,7 +86,7 @@ pub struct Rfc6238<T = Vec<u8>> {
     account_name: String,
 }
 
-impl<T: AsRef<[u8]>> Rfc6238<T> {
+impl Rfc6238 {
     /// Create an [rfc-6238](https://tools.ietf.org/html/rfc6238) compliant set of options that can be turned into a [TOTP](struct.TOTP.html)
     ///
     /// # Errors
@@ -97,10 +97,10 @@ impl<T: AsRef<[u8]>> Rfc6238<T> {
     #[cfg(feature = "otpauth")]
     pub fn new(
         digits: usize,
-        secret: T,
+        secret: Vec<u8>,
         issuer: Option<String>,
         account_name: String,
-    ) -> Result<Rfc6238<T>, Rfc6238Error> {
+    ) -> Result<Rfc6238, Rfc6238Error> {
         assert_digits(&digits)?;
         assert_secret_length(secret.as_ref())?;
 
@@ -137,7 +137,7 @@ impl<T: AsRef<[u8]>> Rfc6238<T> {
     /// - `digits` is lower than 6 or higher than 8
     /// - `secret` is smaller than 128 bits (16 characters)
     #[cfg(feature = "otpauth")]
-    pub fn with_defaults(secret: T) -> Result<Rfc6238<T>, Rfc6238Error> {
+    pub fn with_defaults(secret: Vec<u8>) -> Result<Rfc6238, Rfc6238Error> {
         Rfc6238::new(6, secret, Some("".to_string()), "".to_string())
     }
 
@@ -177,11 +177,11 @@ impl<T: AsRef<[u8]>> TryFrom<Rfc6238<T>> for TOTP<T> {
 }
 
 #[cfg(feature = "otpauth")]
-impl<T: AsRef<[u8]>> TryFrom<Rfc6238<T>> for TOTP<T> {
+impl TryFrom<Rfc6238> for TOTP {
     type Error = TotpUrlError;
 
     /// Try to create a [TOTP](struct.TOTP.html) from a [Rfc6238](struct.Rfc6238.html) config
-    fn try_from(rfc: Rfc6238<T>) -> Result<Self, Self::Error> {
+    fn try_from(rfc: Rfc6238) -> Result<Self, Self::Error> {
         TOTP::new(
             rfc.algorithm,
             rfc.digits,
@@ -289,7 +289,7 @@ mod tests {
     fn rfc_to_totp_fail() {
         let rfc = Rfc6238::new(
             8,
-            GOOD_SECRET.to_string(),
+            GOOD_SECRET.as_bytes().to_vec(),
             ISSUER.map(str::to_string),
             INVALID_ACCOUNT.to_string(),
         )
@@ -304,7 +304,7 @@ mod tests {
     fn rfc_to_totp_ok() {
         let rfc = Rfc6238::new(
             8,
-            GOOD_SECRET.to_string(),
+            GOOD_SECRET.as_bytes().to_vec(),
             ISSUER.map(str::to_string),
             ACCOUNT.to_string(),
         )
@@ -316,7 +316,7 @@ mod tests {
     #[test]
     #[cfg(feature = "otpauth")]
     fn rfc_with_default_set_values() {
-        let mut rfc = Rfc6238::with_defaults(GOOD_SECRET.to_string()).unwrap();
+        let mut rfc = Rfc6238::with_defaults(GOOD_SECRET.as_bytes().to_vec()).unwrap();
         let ok = rfc.digits(8);
         assert!(ok.is_ok());
         assert_eq!(rfc.account_name, "");
@@ -331,7 +331,7 @@ mod tests {
     #[test]
     #[cfg(not(feature = "otpauth"))]
     fn rfc_with_default_set_values() {
-        let mut rfc = Rfc6238::with_defaults(GOOD_SECRET.to_string()).unwrap();
+        let mut rfc = Rfc6238::with_defaults(GOOD_SECRET.as_bytes().to_vec()).unwrap();
         let fail = rfc.digits(4);
         assert!(fail.is_err());
         assert!(matches!(fail.unwrap_err(), Rfc6238Error::InvalidDigits(_)));