diff --git a/libethcore/Ethasher.cpp b/libethcore/Ethasher.cpp
index f80277cb2..e24bfdb6c 100644
--- a/libethcore/Ethasher.cpp
+++ b/libethcore/Ethasher.cpp
@@ -31,7 +31,6 @@
 #include <libdevcrypto/CryptoPP.h>
 #include <libdevcrypto/FileSystem.h>
 #include <libethcore/Params.h>
-#include <libethash/ethash.h>
 #include "BlockInfo.h"
 #include "Ethasher.h"
 using namespace std;
@@ -44,9 +43,9 @@ Ethasher* dev::eth::Ethasher::s_this = nullptr;
 bytes const& Ethasher::cache(BlockInfo const& _header)
 {
 	RecursiveGuard l(x_this);
-	if (_header.number > EPOCH_LENGTH*2048) {
+	if (_header.number > c_ethashEpochLength * 2048) {
 		std::ostringstream error;
-		error << "block number is too high; max is " << EPOCH_LENGTH*2048 << "(was " << _header.number << ")";
+		error << "block number is too high; max is " << c_ethashEpochLength * 2048 << "(was " << _header.number << ")";
 		throw std::invalid_argument( error.str() );
  	}
 
@@ -101,21 +100,20 @@ ethash_params Ethasher::params(unsigned _n)
 
 bool Ethasher::verify(BlockInfo const& _header)
 {
-	if (_header.number >= ETHASH_EPOCH_LENGTH * 2048)
+	if (_header.number >= c_ethashEpochLength * 2048)
 		return false;
+
 	h256 boundary = u256((bigint(1) << 256) / _header.difficulty);
-	uint8_t quickHashOut[32];
-	ethash_quick_hash(
-		quickHashOut,
+
+	// should be equivalent to:
+	auto r = eval(_header);
+	return r.mixHash == _header.mixHash && r.value <= boundary;
+
+	return ethash_quick_check_difficulty(
 		_header.headerHash(WithoutNonce).data(),
 		(uint64_t)(u64)_header.nonce,
-		_header.mixHash.data()
-	);
-	h256 quickHashOut256 = h256(quickHashOut, h256::ConstructFromPointer);
-	if (quickHashOut256 > boundary)
-		return false;
-	auto e = eval(_header, _header.nonce);
-	return (u256)e.value <= boundary && e.mixHash == _header.mixHash;
+		_header.mixHash.data(),
+		boundary.data());
 }
 
 Ethasher::Result Ethasher::eval(BlockInfo const& _header, Nonce const& _nonce)
diff --git a/libethcore/Ethasher.h b/libethcore/Ethasher.h
index 469bbd723..ec8d61225 100644
--- a/libethcore/Ethasher.h
+++ b/libethcore/Ethasher.h
@@ -29,19 +29,8 @@
 #include <libdevcore/Guards.h>
 #include <libdevcrypto/SHA3.h>
 #include <libethash/ethash.h>		// TODO: REMOVE once everything merged into this class and an opaque API can be provided.
-#define ETHASH_REVISION REVISION
-#define ETHASH_DATASET_BYTES_INIT DATASET_BYTES_INIT
-#define ETHASH_DATASET_BYTES_GROWTH DATASET_BYTES_GROWTH
-#define ETHASH_CACHE_BYTES_INIT CACHE_BYTES_INIT
-#define ETHASH_CACHE_BYTES_GROWTH CACHE_BYTES_GROWTH
-#define ETHASH_DAGSIZE_BYTES_INIT DAGSIZE_BYTES_INIT
-#define ETHASH_DAG_GROWTH DAG_GROWTH
-#define ETHASH_EPOCH_LENGTH EPOCH_LENGTH
-#define ETHASH_MIX_BYTES MIX_BYTES
-#define ETHASH_HASH_BYTES HASH_BYTES
-#define ETHASH_DATASET_PARENTS DATASET_PARENTS
-#define ETHASH_CACHE_ROUNDS CACHE_ROUNDS
-#define ETHASH_ACCESSES ACCESSES
+static const unsigned c_ethashRevision = REVISION;
+static const unsigned c_ethashEpochLength = EPOCH_LENGTH;
 #undef REVISION
 #undef DATASET_BYTES_INIT
 #undef DATASET_BYTES_GROWTH
@@ -55,7 +44,6 @@
 #undef DATASET_PARENTS
 #undef CACHE_ROUNDS
 #undef ACCESSES
-
 #include "Common.h"
 #include "BlockInfo.h"