diff --git a/.changelog/unreleased/breaking-changes/1375-allow-null-in-event-attributes.md b/.changelog/unreleased/breaking-changes/1375-allow-null-in-event-attributes.md
new file mode 100644
index 000000000..089e4c6c7
--- /dev/null
+++ b/.changelog/unreleased/breaking-changes/1375-allow-null-in-event-attributes.md
@@ -0,0 +1,4 @@
+- `[tendermint]` Allow null values in `key` and `value` fields of
+  `EventAttribute` when deserializing. The serialization schema for the fields
+  is changed to `Option<String>`
+  ([\#1375](https://github.com/informalsystems/tendermint-rs/issues/1375)).
diff --git a/tendermint/src/abci/event.rs b/tendermint/src/abci/event.rs
index 988145ad8..06e886421 100644
--- a/tendermint/src/abci/event.rs
+++ b/tendermint/src/abci/event.rs
@@ -1,6 +1,7 @@
 use serde::{Deserialize, Serialize};
 
 use crate::prelude::*;
+use crate::serializers;
 
 /// An event that occurred while processing a request.
 ///
@@ -119,8 +120,10 @@ where
 #[derive(Clone, PartialEq, Eq, Debug, Serialize, Deserialize, Hash)]
 pub struct EventAttribute {
     /// The event key.
+    #[serde(with = "serializers::allow_null")]
     pub key: String,
     /// The event value.
+    #[serde(with = "serializers::allow_null")]
     pub value: String,
     /// Whether Tendermint's indexer should index this event.
     ///