diff --git a/crates/client/src/client/schema/block.rs b/crates/client/src/client/schema/block.rs
index 6cc6df25f0d..b4e7d721963 100644
--- a/crates/client/src/client/schema/block.rs
+++ b/crates/client/src/client/schema/block.rs
@@ -77,6 +77,8 @@ pub struct BlockEdge {
 #[cynic(schema_path = "./assets/schema.sdl")]
 pub enum BlockVersion {
     V1,
+    #[cynic(fallback)]
+    Unknown,
 }
 
 /// Block with transaction ids
@@ -123,6 +125,8 @@ pub struct BlockMutation {
 #[cynic(schema_path = "./assets/schema.sdl")]
 pub enum HeaderVersion {
     V1,
+    #[cynic(fallback)]
+    Unknown,
 }
 
 #[derive(cynic::QueryFragment, Clone, Debug)]
diff --git a/crates/client/src/client/types/block.rs b/crates/client/src/client/types/block.rs
index 3f96d34cc6e..e09e6039f32 100644
--- a/crates/client/src/client/types/block.rs
+++ b/crates/client/src/client/types/block.rs
@@ -95,6 +95,7 @@ impl TryFrom<schema::block::Header> for Header {
                 time: value.time.0,
                 application_hash: value.application_hash.into(),
             }),
+            _ => Err(ConversionError::UnknownVariant("HeaderVersion")),
         }
     }
 }
@@ -157,6 +158,7 @@ impl TryFrom<schema::block::Block> for Block {
                     block_producer,
                 })
             }
+            _ => Err(ConversionError::UnknownVariant("BlockVersion")),
         }
     }
 }