diff --git a/.changelog/unreleased/bug-fixes/1247-add-missing-protobuf-impl.md b/.changelog/unreleased/bug-fixes/1247-add-missing-protobuf-impl.md
new file mode 100644
index 0000000000..b4722bd865
--- /dev/null
+++ b/.changelog/unreleased/bug-fixes/1247-add-missing-protobuf-impl.md
@@ -0,0 +1,3 @@
+- Add missing `Protobuf` impl for `ics03_connection::connection::Counterparty` ([#1247])
+
+[#1247]: https://github.com/informalsystems/ibc-rs/issues/1247
diff --git a/modules/src/ics03_connection/connection.rs b/modules/src/ics03_connection/connection.rs
index 7cde7959d4..510ffc9b75 100644
--- a/modules/src/ics03_connection/connection.rs
+++ b/modules/src/ics03_connection/connection.rs
@@ -251,6 +251,8 @@ impl Default for Counterparty {
     }
 }
 
+impl Protobuf<RawCounterparty> for Counterparty {}
+
 // Converts from the wire format RawCounterparty. Typically used from the relayer side
 // during queries for response validation and to extract the Counterparty structure.
 impl TryFrom<RawCounterparty> for Counterparty {