diff --git a/.changelog/unreleased/breaking-changes/249-tendermint-proto-0-40-0.md b/.changelog/unreleased/breaking-changes/249-tendermint-proto-0-40-0.md
new file mode 100644
index 00000000..18ea9ce4
--- /dev/null
+++ b/.changelog/unreleased/breaking-changes/249-tendermint-proto-0-40-0.md
@@ -0,0 +1,2 @@
+- Update `cosmos-sdk-proto` to `v0.26.0`
+  ([\#249](https://github.com/cosmos/ibc-proto-rs/issues/249))
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
index 19fd7808..be6e0da3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,7 +44,7 @@ version          = "0.40.0"
 default-features = false
 
 [dependencies.cosmos-sdk-proto]
-version = "0.25.0"
+version = "0.26.0"
 default-features = false
 
 [dev-dependencies]