diff --git a/libraries/chain/block.cpp b/libraries/chain/block.cpp
index 67e228ef15..a6b3e42132 100644
--- a/libraries/chain/block.cpp
+++ b/libraries/chain/block.cpp
@@ -65,6 +65,7 @@ namespace eosio::chain {
       return results;
    }
 
+   // Does not validate ordering, assumes validate_and_extract_extensions() has been called in verify_qc_claim()
    std::optional<block_extension> signed_block::extract_extension(uint16_t extension_id)const {
       using decompose_t = block_extension_types::decompose_t;
 
@@ -72,6 +73,8 @@ namespace eosio::chain {
          const auto& e = block_extensions[i];
          auto id = e.first;
 
+         if (id > extension_id)
+            break;
          if (id != extension_id)
             continue;
 
diff --git a/libraries/chain/block_header.cpp b/libraries/chain/block_header.cpp
index 4c94d47625..7ac95b9f39 100644
--- a/libraries/chain/block_header.cpp
+++ b/libraries/chain/block_header.cpp
@@ -65,6 +65,7 @@ namespace eosio { namespace chain {
       return results;
    }
 
+   // Does not validate ordering, assumes validate_and_extract_header_extensions() has been called in block_state creation
    std::optional<block_header_extension> block_header::extract_header_extension(uint16_t extension_id)const {
       using decompose_t = block_header_extension_types::decompose_t;
 
@@ -72,6 +73,8 @@ namespace eosio { namespace chain {
          const auto& e = header_extensions[i];
          auto id = e.first;
 
+         if (id > extension_id)
+            break;
          if (id != extension_id)
             continue;