diff --git a/src/script/sign.cpp b/src/script/sign.cpp
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -415,16 +415,16 @@
                    std::vector<uint8_t> &vchSig, const CKeyID &keyid,
                    const CScript &scriptCode) const override {
         // Create a dummy signature that is a valid DER-encoding
-        vchSig.assign(72, '\000');
+        vchSig.assign(71, '\000');
         vchSig[0] = 0x30;
-        vchSig[1] = 69;
+        vchSig[1] = 68;
         vchSig[2] = 0x02;
-        vchSig[3] = 33;
+        vchSig[3] = 32;
         vchSig[4] = 0x01;
-        vchSig[4 + 33] = 0x02;
-        vchSig[5 + 33] = 32;
-        vchSig[6 + 33] = 0x01;
-        vchSig[6 + 33 + 32] = SIGHASH_ALL | SIGHASH_FORKID;
+        vchSig[4 + 32] = 0x02;
+        vchSig[5 + 32] = 32;
+        vchSig[6 + 32] = 0x01;
+        vchSig[6 + 32 + 32] = SIGHASH_ALL | SIGHASH_FORKID;
         return true;
     }
 };
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1415,7 +1415,7 @@
 };
 
 // Calculate the size of the transaction assuming all signatures are max size
-// Use DummySignatureCreator, which inserts 72 byte signatures everywhere.
+// Use DummySignatureCreator, which inserts 71 byte signatures everywhere.
 // NOTE: this requires that all inputs must be in mapWallet (eg the tx should
 // be IsAllFromMe).
 int64_t CalculateMaximumSignedTxSize(const CTransaction &tx,
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1611,7 +1611,7 @@
     return n ? n : nTimeReceived;
 }
 
-// Helper for producing a max-sized low-S signature (eg 72 bytes)
+// Helper for producing a max-sized low-S low-R signature (eg 71 bytes)
 bool CWallet::DummySignInput(CTxIn &tx_in, const CTxOut &txout) const {
     // Fill in dummy signatures for fee calculation.
     const CScript &scriptPubKey = txout.scriptPubKey;
@@ -1626,7 +1626,8 @@
     return true;
 }
 
-// Helper for producing a bunch of max-sized low-S signatures (eg 72 bytes)
+// Helper for producing a bunch of max-sized low-S low-R signatures (eg 71
+// bytes)
 bool CWallet::DummySignTx(CMutableTransaction &txNew,
                           const std::vector<CTxOut> &txouts) const {
     // Fill in dummy signatures for fee calculation.