diff --git a/include/bitcoin/system/chain/block.hpp b/include/bitcoin/system/chain/block.hpp
index 36ee4ba1fa..3432ba6690 100644
--- a/include/bitcoin/system/chain/block.hpp
+++ b/include/bitcoin/system/chain/block.hpp
@@ -109,8 +109,8 @@ class BC_API block
     /// -----------------------------------------------------------------------
 
     /// Consensus checks (no DoS guards for block sync without headers first).
-    code check() const NOEXCEPT;
-    code check(const context& ctx) const NOEXCEPT;
+    code check(bool bypass=false) const NOEXCEPT;
+    code check(const context& ctx, bool bypass=false) const NOEXCEPT;
     code accept(const context& ctx, size_t subsidy_interval,
         uint64_t initial_subsidy) const NOEXCEPT;
     code connect(const context& ctx) const NOEXCEPT;
diff --git a/src/chain/block.cpp b/src/chain/block.cpp
index 32c98432f2..0ef7503389 100644
--- a/src/chain/block.cpp
+++ b/src/chain/block.cpp
@@ -723,8 +723,14 @@ code block::confirm_transactions(const context& ctx) const NOEXCEPT
 // ----------------------------------------------------------------------------
 // The block header is checked/accepted independently.
 
-code block::check() const NOEXCEPT
+code block::check(bool bypass) const NOEXCEPT
 {
+    if (bypass)
+    {
+        return is_invalid_merkle_root() ? error::merkle_mismatch :
+            error::block_success;
+    }
+
     // context free.
     // empty_block is redundant with first_not_coinbase.
     //if (is_empty())
@@ -750,8 +756,15 @@ code block::check() const NOEXCEPT
 // timestamp
 // median_time_past
 
-code block::check(const context& ctx) const NOEXCEPT
+code block::check(const context& ctx, bool bypass) const NOEXCEPT
 {
+    if (bypass)
+    {
+        const auto bip141 = ctx.is_enabled(bip141_rule);
+        return bip141 && is_invalid_witness_commitment() ?
+            error::invalid_witness_commitment : error::block_success;
+    }
+
     const auto bip34 = ctx.is_enabled(bip34_rule);
     const auto bip50 = ctx.is_enabled(bip50_rule);
     const auto bip141 = ctx.is_enabled(bip141_rule);