diff --git a/crypto/codec/codec.go b/crypto/codec/codec.go
index 86451e20..9731d91a 100644
--- a/crypto/codec/codec.go
+++ b/crypto/codec/codec.go
@@ -10,4 +10,5 @@ import (
 // RegisterInterfaces register the Ethermint key concrete types.
 func RegisterInterfaces(registry codectypes.InterfaceRegistry) {
 	registry.RegisterImplementations((*cryptotypes.PubKey)(nil), &ethsecp256k1.PubKey{})
+	registry.RegisterImplementations((*cryptotypes.PrivKey)(nil), &ethsecp256k1.PrivKey{})
 }