diff --git a/signer/src/ecdsa.rs b/signer/src/ecdsa.rs
index 7a5fee996f..8531d4b51c 100644
--- a/signer/src/ecdsa.rs
+++ b/signer/src/ecdsa.rs
@@ -238,7 +238,6 @@ impl std::error::Error for Error {}
 /// since the secret keys are known.
 pub mod dev {
     use super::*;
-    use core::str::FromStr;
 
     once_static_cloned! {
         /// Equivalent to `{DEV_PHRASE}//Alice`.
diff --git a/signer/src/sr25519.rs b/signer/src/sr25519.rs
index f28302b422..9848cbdd68 100644
--- a/signer/src/sr25519.rs
+++ b/signer/src/sr25519.rs
@@ -213,7 +213,6 @@ impl std::error::Error for Error {}
 /// since the secret keys are known.
 pub mod dev {
     use super::*;
-    use core::str::FromStr;
 
     once_static_cloned! {
         /// Equivalent to `{DEV_PHRASE}//Alice`.