diff --git a/tendermint/src/rpc/endpoint/abci_query.rs b/tendermint/src/rpc/endpoint/abci_query.rs
index 218fee6bf..2995948bc 100644
--- a/tendermint/src/rpc/endpoint/abci_query.rs
+++ b/tendermint/src/rpc/endpoint/abci_query.rs
@@ -78,12 +78,20 @@ pub struct AbciQuery {
     pub index: i64,
 
     /// Key
-    // TODO(tarcieri): parse to Vec<u8>?
-    pub key: Option<String>,
+    #[serde(
+        default,
+        serialize_with = "serializers::serialize_option_base64",
+        deserialize_with = "serializers::parse_option_base64"
+    )]
+    pub key: Option<Vec<u8>>,
 
     /// Value
-    // TODO(tarcieri): parse to Vec<u8>?
-    pub value: Option<String>,
+    #[serde(
+        default,
+        serialize_with = "serializers::serialize_option_base64",
+        deserialize_with = "serializers::parse_option_base64"
+    )]
+    pub value: Option<Vec<u8>>,
 
     /// Proof (if requested)
     pub proof: Option<Proof>,
diff --git a/tendermint/tests/integration.rs b/tendermint/tests/integration.rs
index 1367239d4..d5a83b47f 100644
--- a/tendermint/tests/integration.rs
+++ b/tendermint/tests/integration.rs
@@ -33,7 +33,7 @@ mod rpc {
         let abci_query = localhost_rpc_client()
             .abci_query(Some(key), vec![], None, false)
             .unwrap();
-        assert_eq!(abci_query.key.as_ref().unwrap(), "");
+        assert_eq!(abci_query.key.as_ref().unwrap(), &Vec::<u8>::new());
         assert_eq!(abci_query.value.as_ref(), None);
     }