diff --git a/proto/build.rs b/proto/build.rs
index d177e6fb..c613fa99 100644
--- a/proto/build.rs
+++ b/proto/build.rs
@@ -8,6 +8,7 @@ const VEC_BASE64STRING: &str =
     r#"#[serde(with = "tendermint_proto::serializers::bytes::vec_base64string")]"#;
 const OPTION_ANY: &str = r#"#[serde(with = "crate::serializers::option_any")]"#;
 const OPTION_TIMESTAMP: &str = r#"#[serde(with = "crate::serializers::option_timestamp")]"#;
+const DEFAULT_TRUE: &str = r#"#[serde(default = "crate::defaults::default_true")]"#;
 
 #[rustfmt::skip]
 pub static CUSTOM_TYPE_ATTRIBUTES: &[(&str, &str)] = &[
@@ -48,6 +49,8 @@ pub static CUSTOM_FIELD_ATTRIBUTES: &[(&str, &str)] = &[
     (".share.eds.byzantine.pb.BadEncoding.axis", QUOTED),
     (".proof.pb.Proof.nodes", VEC_BASE64STRING),
     (".proof.pb.Proof.leaf_hash", BASE64STRING),
+    // TODO: delete after testnets use node >= 0.11.0-rc14
+    (".proof.pb.Proof.is_max_namespace_ignored", DEFAULT_TRUE),
     (".share.p2p.shrex.nd.NamespaceRowResponse.shares", VEC_BASE64STRING),
 ];
 
diff --git a/proto/src/defaults.rs b/proto/src/defaults.rs
new file mode 100644
index 00000000..1d73eaf9
--- /dev/null
+++ b/proto/src/defaults.rs
@@ -0,0 +1,3 @@
+pub fn default_true() -> bool {
+    true
+}
diff --git a/proto/src/lib.rs b/proto/src/lib.rs
index 982fadbb..657d2c74 100644
--- a/proto/src/lib.rs
+++ b/proto/src/lib.rs
@@ -1,5 +1,6 @@
 #![allow(clippy::all)]
 
+pub mod defaults;
 pub mod serializers;
 
 include!(concat!(env!("OUT_DIR"), "/mod.rs"));