diff --git a/packages/bcp/src/cosmoscodec.ts b/packages/bcp/src/cosmoscodec.ts
index edb76b25..fa5b3c24 100644
--- a/packages/bcp/src/cosmoscodec.ts
+++ b/packages/bcp/src/cosmoscodec.ts
@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/camelcase */
-import { makeSignBytes, marshalTx, unmarshalTx } from "@cosmjs/sdk38";
+import { isStdTx, makeSignBytes, StdTx } from "@cosmjs/sdk38";
 import {
   Address,
   ChainId,
@@ -14,7 +14,7 @@ import {
   TxCodec,
   UnsignedTransaction,
 } from "@iov/bcp";
-import { Bech32 } from "@iov/encoding";
+import { Bech32, fromUtf8, toUtf8 } from "@iov/encoding";
 
 import { pubkeyToAddress } from "./address";
 import { Caip5 } from "./caip5";
@@ -22,6 +22,19 @@ import { parseSignedTx } from "./decode";
 import { buildSignedTx, buildUnsignedTx } from "./encode";
 import { BankToken, nonceToAccountNumber, nonceToSequence } from "./types";
 
+function marshalTx(tx: StdTx): Uint8Array {
+  const json = JSON.stringify(tx);
+  return toUtf8(json);
+}
+
+function unmarshalTx(data: Uint8Array): StdTx {
+  const decoded = JSON.parse(fromUtf8(data));
+  if (!isStdTx(decoded)) {
+    throw new Error("Must be json encoded StdTx");
+  }
+  return decoded;
+}
+
 export class CosmosCodec implements TxCodec {
   private readonly addressPrefix: string;
   private readonly bankTokens: readonly BankToken[];
diff --git a/packages/cli/src/cli.ts b/packages/cli/src/cli.ts
index ce235de6..a7237820 100644
--- a/packages/cli/src/cli.ts
+++ b/packages/cli/src/cli.ts
@@ -69,7 +69,6 @@ export function main(originalArgs: readonly string[]): void {
         "logs",
         "makeCosmoshubPath",
         "makeSignBytes",
-        "marshalTx",
         "IndexedTx",
         "Coin",
         "Msg",
diff --git a/packages/sdk38/src/decoding.ts b/packages/sdk38/src/decoding.ts
deleted file mode 100644
index 8b3752bf..00000000
--- a/packages/sdk38/src/decoding.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import { fromUtf8 } from "@iov/encoding";
-
-import { isStdTx, StdTx } from "./types";
-
-export function unmarshalTx(data: Uint8Array): StdTx {
-  const decoded = JSON.parse(fromUtf8(data));
-  if (!isStdTx(decoded)) {
-    throw new Error("Must be json encoded StdTx");
-  }
-  return decoded;
-}
diff --git a/packages/sdk38/src/encoding.ts b/packages/sdk38/src/encoding.ts
index f01704d0..2d03e0f4 100644
--- a/packages/sdk38/src/encoding.ts
+++ b/packages/sdk38/src/encoding.ts
@@ -1,6 +1,6 @@
 import { toUtf8 } from "@iov/encoding";
 
-import { Msg, StdFee, StdTx } from "./types";
+import { Msg, StdFee } from "./types";
 
 function sortJson(json: any): any {
   if (typeof json !== "object" || json === null) {
@@ -20,11 +20,6 @@ function sortJson(json: any): any {
   return result;
 }
 
-export function marshalTx(tx: StdTx): Uint8Array {
-  const json = JSON.stringify(tx);
-  return toUtf8(json);
-}
-
 interface SignJson {
   readonly account_number: string;
   readonly chain_id: string;
diff --git a/packages/sdk38/src/index.ts b/packages/sdk38/src/index.ts
index f0cfeafb..50ca53e3 100644
--- a/packages/sdk38/src/index.ts
+++ b/packages/sdk38/src/index.ts
@@ -19,8 +19,7 @@ export {
   SearchTxQuery,
   SearchTxFilter,
 } from "./cosmosclient";
-export { unmarshalTx } from "./decoding";
-export { makeSignBytes, marshalTx } from "./encoding";
+export { makeSignBytes } from "./encoding";
 export {
   AuthAccountsResponse,
   BlockResponse,
diff --git a/packages/sdk38/types/decoding.d.ts b/packages/sdk38/types/decoding.d.ts
deleted file mode 100644
index fd0c5746..00000000
--- a/packages/sdk38/types/decoding.d.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-import { StdTx } from "./types";
-export declare function unmarshalTx(data: Uint8Array): StdTx;
diff --git a/packages/sdk38/types/encoding.d.ts b/packages/sdk38/types/encoding.d.ts
index 4d32b80b..e51c7168 100644
--- a/packages/sdk38/types/encoding.d.ts
+++ b/packages/sdk38/types/encoding.d.ts
@@ -1,5 +1,4 @@
-import { Msg, StdFee, StdTx } from "./types";
-export declare function marshalTx(tx: StdTx): Uint8Array;
+import { Msg, StdFee } from "./types";
 export declare function makeSignBytes(
   msgs: readonly Msg[],
   fee: StdFee,
diff --git a/packages/sdk38/types/index.d.ts b/packages/sdk38/types/index.d.ts
index 2823e7e2..7a9de872 100644
--- a/packages/sdk38/types/index.d.ts
+++ b/packages/sdk38/types/index.d.ts
@@ -17,8 +17,7 @@ export {
   SearchTxQuery,
   SearchTxFilter,
 } from "./cosmosclient";
-export { unmarshalTx } from "./decoding";
-export { makeSignBytes, marshalTx } from "./encoding";
+export { makeSignBytes } from "./encoding";
 export {
   AuthAccountsResponse,
   BlockResponse,