diff --git a/src/Nimiq/Transaction.cpp b/src/Nimiq/Transaction.cpp
index e5ba42006fe..9a832240ce6 100644
--- a/src/Nimiq/Transaction.cpp
+++ b/src/Nimiq/Transaction.cpp
@@ -9,13 +9,14 @@
 
 namespace TW::Nimiq {
 
-const uint8_t NETWORK_ID = 42;
+const uint8_t NETWORK_ID = 24;
 const uint8_t EMPTY_FLAGS = 0;
 
 std::vector<uint8_t> Transaction::serialize() const {
     std::vector<uint8_t> data;
 
     data.push_back(0x00); // Basic TX type
+    data.push_back(0x00); // Signature Proof type and flags (Ed25519 type and no flags)
     data.insert(data.end(), sender_pub_key.begin(), sender_pub_key.end());
     data.insert(data.end(), destination.bytes.begin(), destination.bytes.end());
     encode64BE(amount, data);
@@ -42,6 +43,7 @@ std::vector<uint8_t> Transaction::getPreImage() const {
     encode32BE(vsh, data);
     data.push_back(NETWORK_ID);
     data.push_back(EMPTY_FLAGS);
+    data.push_back(0x00); // Sender Data size (+ 0 bytes of data)
 
     return data;
 }
diff --git a/swift/Tests/Blockchains/NimiqTests.swift b/swift/Tests/Blockchains/NimiqTests.swift
index 8ee8dac51ed..1c89cd6d74c 100644
--- a/swift/Tests/Blockchains/NimiqTests.swift
+++ b/swift/Tests/Blockchains/NimiqTests.swift
@@ -18,6 +18,6 @@ class NimiqTests: XCTestCase {
 
         let output: NimiqSigningOutput = AnySigner.sign(input: input, coin: .nimiq)
 
-        XCTAssertEqual(output.encoded.hexString, "0070c7492aaa9c9ac7a05bc0d9c5db2dae9372029654f71f0c7f95deed5099b7021450ffc385cd4e7c6ac9a7e91614ca67ff90568a00000000028182ba00000000000003e80004cb2f2a74dc7f6e0ab58a0bf52cc6e8801b0cca132dd4229d9a3e3a3d2f90e4d8f045d981b771bf5fc3851a98f3c617b1a943228f963e910e061808a721cfa0e3cad50b")
+        XCTAssertEqual(output.encoded.hexString, "000070c7492aaa9c9ac7a05bc0d9c5db2dae9372029654f71f0c7f95deed5099b7021450ffc385cd4e7c6ac9a7e91614ca67ff90568a00000000028182ba00000000000003e80004cb2f180ba678744be3bf9cd44fbcdabfb5be209f21739934836e26055610ab02720fa99489219d9f3581664473a1b40b30ad1f6e13150d59f8234a42c3f0de3d505405")
     }
 }
diff --git a/tests/chains/Nimiq/SignerTests.cpp b/tests/chains/Nimiq/SignerTests.cpp
index c22441f2f39..e29208e10ec 100644
--- a/tests/chains/Nimiq/SignerTests.cpp
+++ b/tests/chains/Nimiq/SignerTests.cpp
@@ -37,7 +37,7 @@ TEST(NimiqSigner, Sign) {
     signer.sign(privateKey, tx);
 
     ASSERT_EQ(hex(tx.signature),
-        "74dc7f6e0ab58a0bf52cc6e8801b0cca132dd4229d9a3e3a3d2f90e4d8f045d981b771bf5fc3851a98f3c617b1a943228f963e910e061808a721cfa0e3cad50b");
+        "0ba678744be3bf9cd44fbcdabfb5be209f21739934836e26055610ab02720fa99489219d9f3581664473a1b40b30ad1f6e13150d59f8234a42c3f0de3d505405");
 }
 
 } // namespace TW::Nimiq
diff --git a/tests/chains/Nimiq/TWAnySignerTests.cpp b/tests/chains/Nimiq/TWAnySignerTests.cpp
index a618b1ac04f..3d0cb3d9327 100644
--- a/tests/chains/Nimiq/TWAnySignerTests.cpp
+++ b/tests/chains/Nimiq/TWAnySignerTests.cpp
@@ -25,7 +25,7 @@ TEST(TWAnySignerNimiq, Sign) {
     Proto::SigningOutput output;
     ANY_SIGN(input, TWCoinTypeNimiq);
 
-    EXPECT_EQ(hex(output.encoded()), "0070c7492aaa9c9ac7a05bc0d9c5db2dae9372029654f71f0c7f95deed5099b7021450ffc385cd4e7c6ac9a7e91614ca67ff90568a00000000028182ba00000000000003e80004cb2f2a74dc7f6e0ab58a0bf52cc6e8801b0cca132dd4229d9a3e3a3d2f90e4d8f045d981b771bf5fc3851a98f3c617b1a943228f963e910e061808a721cfa0e3cad50b");
+    EXPECT_EQ(hex(output.encoded()), "000070c7492aaa9c9ac7a05bc0d9c5db2dae9372029654f71f0c7f95deed5099b7021450ffc385cd4e7c6ac9a7e91614ca67ff90568a00000000028182ba00000000000003e80004cb2f180ba678744be3bf9cd44fbcdabfb5be209f21739934836e26055610ab02720fa99489219d9f3581664473a1b40b30ad1f6e13150d59f8234a42c3f0de3d505405");
 }
 
 } // namespace TW::Nimiq::tests
diff --git a/tests/chains/Nimiq/TransactionTests.cpp b/tests/chains/Nimiq/TransactionTests.cpp
index 679f955f4ca..90e6381a0e2 100644
--- a/tests/chains/Nimiq/TransactionTests.cpp
+++ b/tests/chains/Nimiq/TransactionTests.cpp
@@ -25,7 +25,7 @@ TEST(NimiqTransaction, PreImage) {
         314159
     );
     ASSERT_EQ(hex(tx.getPreImage()),
-        "000082d5f776378ccbe34a3d941f22d4715bc9f81e0d001450ffc385cd4e7c6ac9a7e91614ca67ff90568a0000000000028182ba00000000000003e80004cb2f2a00");
+        "000082d5f776378ccbe34a3d941f22d4715bc9f81e0d001450ffc385cd4e7c6ac9a7e91614ca67ff90568a0000000000028182ba00000000000003e80004cb2f180000");
 }
 
 TEST(NimiqTransaction, Serialize) {
@@ -42,11 +42,11 @@ TEST(NimiqTransaction, Serialize) {
         314159
     );
 
-    const auto signature = parse_hex("74dc7f6e0ab58a0bf52cc6e8801b0cca132dd4229d9a3e3a3d2f90e4d8f045d981b771bf5fc3851a98f3c617b1a943228f963e910e061808a721cfa0e3cad50b");
+    const auto signature = parse_hex("0ba678744be3bf9cd44fbcdabfb5be209f21739934836e26055610ab02720fa99489219d9f3581664473a1b40b30ad1f6e13150d59f8234a42c3f0de3d505405");
     std::copy(signature.begin(), signature.end(), tx.signature.begin());
 
     ASSERT_EQ(hex(tx.serialize()),
-        "0070c7492aaa9c9ac7a05bc0d9c5db2dae9372029654f71f0c7f95deed5099b7021450ffc385cd4e7c6ac9a7e91614ca67ff90568a00000000028182ba00000000000003e80004cb2f2a74dc7f6e0ab58a0bf52cc6e8801b0cca132dd4229d9a3e3a3d2f90e4d8f045d981b771bf5fc3851a98f3c617b1a943228f963e910e061808a721cfa0e3cad50b");
+        "000070c7492aaa9c9ac7a05bc0d9c5db2dae9372029654f71f0c7f95deed5099b7021450ffc385cd4e7c6ac9a7e91614ca67ff90568a00000000028182ba00000000000003e80004cb2f180ba678744be3bf9cd44fbcdabfb5be209f21739934836e26055610ab02720fa99489219d9f3581664473a1b40b30ad1f6e13150d59f8234a42c3f0de3d505405");
 }
 
 } // namespace TW::Nimiq