diff --git a/.changelog/unreleased/bug-fixes/1239-consider-client-expired-at-trusting-period.md b/.changelog/unreleased/bug-fixes/1239-consider-client-expired-at-trusting-period.md
new file mode 100644
index 000000000..3f2ecbcd2
--- /dev/null
+++ b/.changelog/unreleased/bug-fixes/1239-consider-client-expired-at-trusting-period.md
@@ -0,0 +1,3 @@
+- [ibc-client-tendermint] Expire a client when the elapsed time from a trusted
+  header equals the trusting period, to stay consistent with the expiry logic in
+  `tendermint-rs` ([\#1239](https://github.com/cosmos/ibc-rs/issues/1239))
diff --git a/ibc-clients/ics07-tendermint/src/client_state/validation.rs b/ibc-clients/ics07-tendermint/src/client_state/validation.rs
index 116b84dd8..4a7f7f6a3 100644
--- a/ibc-clients/ics07-tendermint/src/client_state/validation.rs
+++ b/ibc-clients/ics07-tendermint/src/client_state/validation.rs
@@ -221,7 +221,10 @@ where
     if let Some(elapsed_since_latest_consensus_state) =
         now.duration_since(&latest_consensus_state.timestamp().into())
     {
-        if elapsed_since_latest_consensus_state > client_state.trusting_period {
+        // Note: The equality is considered as expired to stay consistent with
+        // the check in tendermint-rs, where a header at `trusted_header_time +
+        // trusting_period` is considered expired.
+        if elapsed_since_latest_consensus_state >= client_state.trusting_period {
             return Ok(Status::Expired);
         }
     }