diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
index 9cb3d251..d00a3120 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
@@ -67,7 +67,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("HjSC7VkhKih6xMhudlqfaFE8ZZnP8RKJPv4iqR7RhcE="),
         },
-        votingPower: undefined,
+        votingPower: 0,
       });
     });
   });
diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
index 9413696a..f4ac865f 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
@@ -257,13 +257,14 @@ function decodeConsensusParams(data: RpcConsensusParams): responses.ConsensusPar
 // for block results
 interface RpcValidatorUpdate {
   readonly pub_key: RpcPubkey;
+  // When omitted, this means zero (see https://github.com/cosmos/cosmjs/issues/1177#issuecomment-1160115080)
   readonly power?: string;
 }
 
 export function decodeValidatorUpdate(data: RpcValidatorUpdate): responses.ValidatorUpdate {
   return {
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: data.power ? Integer.parse(data.power) : undefined,
+    votingPower: Integer.parse(data.power ?? 0),
   };
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint34/responses.ts b/packages/tendermint-rpc/src/tendermint34/responses.ts
index 3ae52527..c9d1ec41 100644
--- a/packages/tendermint-rpc/src/tendermint34/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint34/responses.ts
@@ -356,7 +356,7 @@ export interface Validator {
 
 export interface ValidatorUpdate {
   readonly pubkey: ValidatorPubkey;
-  readonly votingPower?: number;
+  readonly votingPower: number;
 }
 
 export interface ConsensusParams {
diff --git a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts
index 9cb3d251..d00a3120 100644
--- a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts
@@ -67,7 +67,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("HjSC7VkhKih6xMhudlqfaFE8ZZnP8RKJPv4iqR7RhcE="),
         },
-        votingPower: undefined,
+        votingPower: 0,
       });
     });
   });
diff --git a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts
index 90b2db0b..3fd99ce3 100644
--- a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts
@@ -259,13 +259,14 @@ function decodeConsensusParams(data: RpcConsensusParams): responses.ConsensusPar
 // for block results
 interface RpcValidatorUpdate {
   readonly pub_key: RpcPubkey;
+  // When omitted, this means zero (see https://github.com/cosmos/cosmjs/issues/1177#issuecomment-1160115080)
   readonly power?: string;
 }
 
 export function decodeValidatorUpdate(data: RpcValidatorUpdate): responses.ValidatorUpdate {
   return {
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: data.power ? Integer.parse(data.power) : undefined,
+    votingPower: Integer.parse(data.power ?? 0),
   };
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint35/responses.ts b/packages/tendermint-rpc/src/tendermint35/responses.ts
index be2eecca..d1e9f5a8 100644
--- a/packages/tendermint-rpc/src/tendermint35/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint35/responses.ts
@@ -361,7 +361,7 @@ export interface Validator {
 
 export interface ValidatorUpdate {
   readonly pubkey: ValidatorPubkey;
-  readonly votingPower?: number;
+  readonly votingPower: number;
 }
 
 export interface ConsensusParams {