diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d39c116..dd866eac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,8 @@
 - @cosmjs/cosmwasm: Add `CosmWasmClient.getTx` method for searching by ID and
   remove such functionality from `CosmWasmClient.searchTx`.
 - @cosmjs/cosmwasm-stargate: Add new package for CosmWasm Stargate support.
+- @cosmjs/crypto: Change `Secp256k1Keypair` from tagged type to simple
+  interface.
 - @cosmjs/launchpad: Add `Secp256k1Wallet` to manage a single raw secp256k1
   keypair.
 - @cosmjs/launchpad: `OfflineSigner` type’s `sign` method renamed `signAmino`
diff --git a/packages/crypto/src/secp256k1.ts b/packages/crypto/src/secp256k1.ts
index ec05ed8e..d9357f98 100644
--- a/packages/crypto/src/secp256k1.ts
+++ b/packages/crypto/src/secp256k1.ts
@@ -1,20 +1,17 @@
 import { fromHex, toHex } from "@cosmjs/encoding";
 import BN from "bn.js";
 import elliptic from "elliptic";
-import { As } from "type-tagger";
 
 import { ExtendedSecp256k1Signature, Secp256k1Signature } from "./secp256k1signature";
 
 const secp256k1 = new elliptic.ec("secp256k1");
 const secp256k1N = new BN("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", "hex");
 
-interface Keypair {
+export interface Secp256k1Keypair {
   readonly pubkey: Uint8Array;
   readonly privkey: Uint8Array;
 }
 
-export type Secp256k1Keypair = Keypair & As<"secp256k1-keypair">;
-
 export class Secp256k1 {
   public static async makeKeypair(privkey: Uint8Array): Promise<Secp256k1Keypair> {
     if (privkey.length !== 32) {
@@ -35,7 +32,7 @@ export class Secp256k1 {
       throw new Error("input data is not a valid secp256k1 private key");
     }
 
-    const out: Keypair = {
+    const out: Secp256k1Keypair = {
       privkey: fromHex(keypair.getPrivate("hex")),
       // encodes uncompressed as
       // - 1-byte prefix "04"
@@ -43,7 +40,7 @@ export class Secp256k1 {
       // - 32-byte y coordinate
       pubkey: Uint8Array.from(keypair.getPublic("array")),
     };
-    return out as Secp256k1Keypair;
+    return out;
   }
 
   // Creates a signature that is
diff --git a/packages/crypto/types/secp256k1.d.ts b/packages/crypto/types/secp256k1.d.ts
index 7f0e6653..1b0d1422 100644
--- a/packages/crypto/types/secp256k1.d.ts
+++ b/packages/crypto/types/secp256k1.d.ts
@@ -1,10 +1,8 @@
-import { As } from "type-tagger";
 import { ExtendedSecp256k1Signature, Secp256k1Signature } from "./secp256k1signature";
-interface Keypair {
+export interface Secp256k1Keypair {
   readonly pubkey: Uint8Array;
   readonly privkey: Uint8Array;
 }
-export declare type Secp256k1Keypair = Keypair & As<"secp256k1-keypair">;
 export declare class Secp256k1 {
   static makeKeypair(privkey: Uint8Array): Promise<Secp256k1Keypair>;
   static createSignature(messageHash: Uint8Array, privkey: Uint8Array): Promise<ExtendedSecp256k1Signature>;
@@ -17,4 +15,3 @@ export declare class Secp256k1 {
   static compressPubkey(pubkey: Uint8Array): Uint8Array;
   static trimRecoveryByte(signature: Uint8Array): Uint8Array;
 }
-export {};