diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -937,9 +937,11 @@
 
                         bool fSuccess = false;
                         if (vchSig.size()) {
-                            CHashWriter ss(SER_GETHASH, 0);
-                            ss << vchMessage;
-                            uint256 message = ss.GetHash();
+                            valtype vchHash(32);
+                            CSHA256()
+                                .Write(vchMessage.data(), vchMessage.size())
+                                .Finalize(vchHash.data());
+                            uint256 message(vchHash);
                             CPubKey pubkey(vchPubKey);
                             fSuccess = pubkey.Verify(message, vchSig);
                         }
diff --git a/src/test/checkdatasig_tests.cpp b/src/test/checkdatasig_tests.cpp
--- a/src/test/checkdatasig_tests.cpp
+++ b/src/test/checkdatasig_tests.cpp
@@ -104,10 +104,9 @@
 
     // Check various pubkey encoding.
     const valtype message{};
-
-    CHashWriter ss(SER_GETHASH, 0);
-    ss << message;
-    uint256 messageHash = ss.GetHash();
+    valtype vchHash(32);
+    CSHA256().Write(message.data(), message.size()).Finalize(vchHash.data());
+    uint256 messageHash(vchHash);
 
     KeyData kd;
     valtype pubkey = ToByteVector(kd.pubkey);
diff --git a/src/test/data/script_tests.json b/src/test/data/script_tests.json
--- a/src/test/data/script_tests.json
+++ b/src/test/data/script_tests.json
@@ -2201,21 +2201,21 @@
     "P2PK REPLAY PROTECTED"
 ],
 [
-    "0x46 0x304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312 0",
+    "0x46 0x30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "OK",
     "Standard CHECKDATASIG"
 ],
 [
-    "0x46 0x304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312 1",
+    "0x46 0x30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07 1",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG NOT",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "NULLFAIL",
     "CHECKDATASIG with NULLFAIL flags"
 ],
 [
-    "0x46 0x304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312 1",
+    "0x46 0x30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07 1",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG NOT",
     "CHECKDATASIG,STRICTENC",
     "OK",
@@ -2229,77 +2229,77 @@
     "CHECKDATASIG empty signature"
 ],
 [
-    "0x47 0x304502203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022100a81a1d08c5c192a1efc94316b5d15befece6f4cca32c143e54949cfadb245e2f 0",
+    "0x47 0x30450220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a4022100a31d6133ec962903e4ae68812c70550aa994f92891c9c08be802af816fd4843a 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "OK",
     "CHECKDATASIG with High S but no Low S"
 ],
 [
-    "0x47 0x304502203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022100a81a1d08c5c192a1efc94316b5d15befece6f4cca32c143e54949cfadb245e2f 0",
+    "0x47 0x30450220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a4022100a31d6133ec962903e4ae68812c70550aa994f92891c9c08be802af816fd4843a 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG",
     "CHECKDATASIG,LOW_S,NULLFAIL,STRICTENC",
     "SIG_HIGH_S",
     "CHECKDATASIG with High S"
 ],
 [
-    "0x46 0x30440220ad3ed8d119bcbc02c6c7b1ad02441d22f9a5afe0171b2384d7989ef2d58832ce02201074e2e35779b0d1f99b350ff0f445ee0045c5530f1dff1186547cf7cc16935b 0",
+    "0x46 0x3044022090c2b41ac64aea5808a991dac049bf6a98816f8610b4028cd371e68a23b0cd47022073310757507b168533cc141e3243416cf2c55e3b4525655abf5c97c8724a68aa 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL",
     "OK",
     "CHECKDATASIG with too little R padding but no DERSIG"
 ],
 [
-    "0x46 0x30440220ad3ed8d119bcbc02c6c7b1ad02441d22f9a5afe0171b2384d7989ef2d58832ce02201074e2e35779b0d1f99b350ff0f445ee0045c5530f1dff1186547cf7cc16935b 0",
+    "0x46 0x3044022090c2b41ac64aea5808a991dac049bf6a98816f8610b4028cd371e68a23b0cd47022073310757507b168533cc141e3243416cf2c55e3b4525655abf5c97c8724a68aa 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "SIG_DER",
     "CHECKDATASIG with too little R padding"
 ],
 [
-    "0x46 0x3044022020eaad358efbbbe38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6f466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL",
     "OK",
     "CHECKDATASIG with hybrid pubkey but no STRICTENC"
 ],
 [
-    "0x46 0x3044022020eaad358efbbbe38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6f466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "PUBKEYTYPE",
     "CHECKDATASIG with hybrid pubkey"
 ],
 [
-    "0x46 0x3044022020eaad358efbbae38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6e466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIG NOT",
     "CHECKDATASIG",
     "OK",
     "CHECKDATASIG with invalid hybrid pubkey but no STRICTENC"
 ],
 [
-    "0x46 0x3044022020eaad358efbbae38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6e466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIG",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "PUBKEYTYPE",
     "CHECKDATASIG with invalid hybrid pubkey"
 ],
 [
-    "0x46 0x304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312 0",
+    "0x46 0x30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "OK",
     "Standard CHECKDATASIGVERIFY"
 ],
 [
-    "0x46 0x304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312 1",
+    "0x46 0x30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07 1",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "NULLFAIL",
     "CHECKDATASIGVERIFY with NULLFAIL flags"
 ],
 [
-    "0x46 0x304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312 1",
+    "0x46 0x30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07 1",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,STRICTENC",
     "CHECKDATASIGVERIFY",
@@ -2313,56 +2313,56 @@
     "CHECKDATASIGVERIFY empty signature"
 ],
 [
-    "0x47 0x304502203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022100a81a1d08c5c192a1efc94316b5d15befece6f4cca32c143e54949cfadb245e2f 0",
+    "0x47 0x30450220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a4022100a31d6133ec962903e4ae68812c70550aa994f92891c9c08be802af816fd4843a 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "OK",
     "CHECKDATASIG with High S but no Low S"
 ],
 [
-    "0x47 0x304502203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022100a81a1d08c5c192a1efc94316b5d15befece6f4cca32c143e54949cfadb245e2f 0",
+    "0x47 0x30450220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a4022100a31d6133ec962903e4ae68812c70550aa994f92891c9c08be802af816fd4843a 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,LOW_S,NULLFAIL,STRICTENC",
     "SIG_HIGH_S",
     "CHECKDATASIG with High S"
 ],
 [
-    "0x46 0x30440220ad3ed8d119bcbc02c6c7b1ad02441d22f9a5afe0171b2384d7989ef2d58832ce02201074e2e35779b0d1f99b350ff0f445ee0045c5530f1dff1186547cf7cc16935b 0",
+    "0x46 0x3044022090c2b41ac64aea5808a991dac049bf6a98816f8610b4028cd371e68a23b0cd47022073310757507b168533cc141e3243416cf2c55e3b4525655abf5c97c8724a68aa 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL",
     "OK",
     "CHECKDATASIGVERIFY with too little R padding but no DERSIG"
 ],
 [
-    "0x46 0x30440220ad3ed8d119bcbc02c6c7b1ad02441d22f9a5afe0171b2384d7989ef2d58832ce02201074e2e35779b0d1f99b350ff0f445ee0045c5530f1dff1186547cf7cc16935b 0",
+    "0x46 0x3044022090c2b41ac64aea5808a991dac049bf6a98816f8610b4028cd371e68a23b0cd47022073310757507b168533cc141e3243416cf2c55e3b4525655abf5c97c8724a68aa 0",
     "0x21 0x038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "SIG_DER",
     "CHECKDATASIGVERIFY with too little R padding"
 ],
 [
-    "0x46 0x3044022020eaad358efbbbe38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6f466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL",
     "OK",
     "CHECKDATASIGVERIFY with hybrid pubkey but no STRICTENC"
 ],
 [
-    "0x46 0x3044022020eaad358efbbbe38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6f466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "PUBKEYTYPE",
     "CHECKDATASIGVERIFY with hybrid pubkey"
 ],
 [
-    "0x46 0x3044022020eaad358efbbae38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6e466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG",
     "CHECKDATASIGVERIFY",
     "CHECKDATASIGVERIFY with invalid hybrid pubkey but no STRICTENC"
 ],
 [
-    "0x46 0x3044022020eaad358efbbae38655a0c9a1bbaa6bd85037d5c2ebb813b57dcfb55621f57202206b25bf677746f2347be832d0dba6fe80e081ba693a46222d5bdfbdb33ae2c297 0",
+    "0x46 0x3044022077c8d336572f6e466055b5f70f433851f8f535f6c4fc71133a6cfd71079d03b702200ed9f5eb8aa5b266abac35d416c3207e7a538bf5f37649727d7a9823b1069577 0",
     "0x41 0x0679be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKDATASIGVERIFY 1",
     "CHECKDATASIG,NULLFAIL,STRICTENC",
     "PUBKEYTYPE",
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -1,4 +1,5 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
+// Copyright (c) 2017-2018 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -344,10 +345,10 @@
 
     TestBuilder &PushDataSig(const CKey &key, const std::vector<uint8_t> &data,
                              unsigned int lenR = 32, unsigned int lenS = 32) {
-        CHashWriter ss(SER_GETHASH, 0);
-        ss << data;
+        std::vector<uint8_t> vchHash(32);
+        CSHA256().Write(data.data(), data.size()).Finalize(vchHash.data());
 
-        DoPush(DoSign(key, ss.GetHash(), lenR, lenS));
+        DoPush(DoSign(key, uint256(vchHash), lenR, lenS));
         return *this;
     }
 
diff --git a/test/functional/abc-checkdatasig-activation.py b/test/functional/abc-checkdatasig-activation.py
--- a/test/functional/abc-checkdatasig-activation.py
+++ b/test/functional/abc-checkdatasig-activation.py
@@ -47,7 +47,7 @@
         tx.vin = [CTxIn(COutPoint(int(utxo["txid"], 16), utxo["vout"]))]
         tx.vout = []
         signature = bytearray.fromhex(
-            '304402203fcefd3a307407b8580565aa41fa57ef8fbfc9470cccab19ed111b3d009b01b8022057e5e2f73a3e6d5e1036bce94a2ea40ecdc7e81a0c1c8bfd6b3dc191f511e312')
+            '30440220256c12175e809381f97637933ed6ab97737d263eaaebca6add21bced67fd12a402205ce29ecc1369d6fc1b51977ed38faaf41119e3be1d7edfafd7cfaf0b6061bd07')
         message = bytearray.fromhex('')
         pubkey = bytearray.fromhex(
             '038282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f51508')