diff --git a/include/bitcoin/system/error/block_error_t.hpp b/include/bitcoin/system/error/block_error_t.hpp
index ea7c0fdd94..59dd0607f8 100644
--- a/include/bitcoin/system/error/block_error_t.hpp
+++ b/include/bitcoin/system/error/block_error_t.hpp
@@ -55,7 +55,6 @@ enum block_error_t : uint8_t
     forward_reference,
     merkle_mismatch,
     block_legacy_sigop_limit,
-    malleable_identifier,
 
     // accept block
     block_non_final,
diff --git a/src/error/block_error_t.cpp b/src/error/block_error_t.cpp
index 739cbd075a..456ee9e6e5 100644
--- a/src/error/block_error_t.cpp
+++ b/src/error/block_error_t.cpp
@@ -49,7 +49,6 @@ DEFINE_ERROR_T_MESSAGE_MAP(block_error)
     { forward_reference, "transactions out of order" },
     { merkle_mismatch, "merkle root mismatch" },
     { block_legacy_sigop_limit, "too many block legacy signature operations" },
-    { malleable_identifier, "block identifier is malleable" },
 
     // accept block
     { block_non_final, "block contains a non-final transaction" },
diff --git a/test/error/block_error_t.cpp b/test/error/block_error_t.cpp
index b55b4b54c1..e6f9fffb8f 100644
--- a/test/error/block_error_t.cpp
+++ b/test/error/block_error_t.cpp
@@ -172,15 +172,6 @@ BOOST_AUTO_TEST_CASE(block_error_t__code__block_legacy_sigop_limit__true_exected
     BOOST_REQUIRE_EQUAL(ec.message(), "too many block legacy signature operations");
 }
 
-BOOST_AUTO_TEST_CASE(block_error_t__code__malleable_identifier__true_exected_message)
-{
-    constexpr auto value = error::malleable_identifier;
-    const auto ec = code(value);
-    BOOST_REQUIRE(ec);
-    BOOST_REQUIRE(ec == value);
-    BOOST_REQUIRE_EQUAL(ec.message(), "block identifier is malleable");
-}
-
 // accept block
 
 BOOST_AUTO_TEST_CASE(block_error_t__code__block_non_final__true_exected_message)