diff --git a/subxt/src/backend/unstable/mod.rs b/subxt/src/backend/unstable/mod.rs
index f2fcd22346..04ab4bcea5 100644
--- a/subxt/src/backend/unstable/mod.rs
+++ b/subxt/src/backend/unstable/mod.rs
@@ -599,9 +599,9 @@ impl<T: Config + Send + Sync + 'static> Backend<T> for UnstableBackend<T> {
                                 }
                                 SeenBlock::Finalized(block_refs) => {
                                     for block_ref in block_refs {
-                                        // if !seen_blocks.contains_key(&block_ref.hash()) {
-                                        //     panic!("Finalized before new Finalized {:#?}\n initBlock {:#?} \nMEMLOG{:#?}\n SeenBlocks{:#?} \n Other{:#?}", block_ref.hash(), unsafe { &FIN_BLOCK }, mem_log, seen_blocks, seen_other);
-                                        // }
+                                        if !seen_blocks.contains_key(&block_ref.hash()) {
+                                            panic!("Finalized before new Finalized {:#?}\n initBlock {:#?} \nMEMLOG{:#?}\n SeenBlocks{:#?} \n Other{:#?}", block_ref.hash(), unsafe { &FIN_BLOCK }, mem_log, seen_blocks, seen_other);
+                                        }
 
                                         let entry =
                                             seen_blocks.entry(block_ref.hash()).or_insert((