diff --git a/Cargo.toml b/Cargo.toml
index a97f4fa..9e7c673 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,12 +10,12 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-failure = "0.1"
 num-bigint = "0.2"
 num-bigint-dig = "0.4"
 num-traits = "0.2"
 pem = "0.4"
 rsa = "0.1.3"
+thiserror = "1.0.9"
 yasna = { version = "0.3", features = ["num-bigint"] }
 
 [dev-dependencies]
diff --git a/src/lib.rs b/src/lib.rs
index a9891eb..24dfa9a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-use failure::Fail;
+use thiserror::Error;
 use num_bigint_dig::{BigInt, BigUint, Sign};
 
 mod private;
@@ -17,21 +17,21 @@ pub trait KeyExt {
         Self: Sized;
 }
 
-#[derive(Debug, Fail)]
+#[derive(Debug, Error)]
 pub enum KeyError {
-    #[fail(display = "Invalid key kind supplied")]
+    #[error("Invalid key kind supplied")]
     Kind,
 
-    #[fail(display = "Key not PEM-formatted")]
+    #[error("Key not PEM-formatted")]
     Pem,
 
-    #[fail(display = "Error parsing key, {}", _0)]
-    Parse(#[cause] yasna::ASN1Error),
+    #[error("Error parsing key, {}", .0)]
+    Parse(#[from] yasna::ASN1Error),
 
-    #[fail(display = "Constructed key is invalid")]
+    #[error("Constructed key is invalid")]
     Validate,
 
-    #[fail(display = "Could not serialize key")]
+    #[error("Could not serialize key")]
     Serialize,
 }
 
@@ -56,12 +56,6 @@ fn sign_from_dig(sign: Sign) -> num_bigint::Sign {
     }
 }
 
-impl From<yasna::ASN1Error> for KeyError {
-    fn from(e: yasna::ASN1Error) -> Self {
-        KeyError::Parse(e)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use crate::KeyExt;