diff --git a/hedera-node/hapi-utils/src/main/java/com/hedera/node/app/hapi/utils/ethereum/EthTxData.java b/hedera-node/hapi-utils/src/main/java/com/hedera/node/app/hapi/utils/ethereum/EthTxData.java
index 13025f545903..99546d2e2fd1 100644
--- a/hedera-node/hapi-utils/src/main/java/com/hedera/node/app/hapi/utils/ethereum/EthTxData.java
+++ b/hedera-node/hapi-utils/src/main/java/com/hedera/node/app/hapi/utils/ethereum/EthTxData.java
@@ -21,7 +21,6 @@
 import java.util.Objects;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
-import org.bouncycastle.util.BigIntegers;
 
 public record EthTxData(
         byte[] rawTx,
@@ -111,6 +110,20 @@ public static int getTransactionType(byte[] data) {
         }
     }
 
+    /// Returns an unsigned byte[] representation of a BigInteger, dropping the leading zero byte
+    /// if present. Adopted from org.bouncycastle.util.BigIntegers.asUnsignedByteArray().
+    public static byte[] asUnsignedByteArray(final BigInteger value) {
+        final byte[] bytes = value.toByteArray();
+
+        if (bytes[0] == 0 && bytes.length != 1) {
+            final byte[] tmp = new byte[bytes.length - 1];
+            System.arraycopy(bytes, 1, tmp, 0, tmp.length);
+            return tmp;
+        }
+
+        return bytes;
+    }
+
     public EthTxData replaceCallData(final byte[] newCallData) {
         return new EthTxData(
                 null,
@@ -770,9 +783,9 @@ private static byte[] deriveChainId(@NonNull final BigInteger vBI) {
             // after EIP155 the chain id is equal to CHAIN_ID = (v - {0,1} - 35) / 2.
             // asUnsignedByteArray avoids the leading sign byte BigInteger.toByteArray adds when the
             // top bit is set — see https://github.com/hashgraph/hedera-services/issues/15953
-            return BigIntegers.asUnsignedByteArray(BigInteger.valueOf((v - 35) >> 1));
+            return EthTxData.asUnsignedByteArray(BigInteger.valueOf((v - 35) >> 1));
         }
-        return BigIntegers.asUnsignedByteArray(
+        return EthTxData.asUnsignedByteArray(
                 vBI.subtract(BigInteger.valueOf(35)).shiftRight(1));
     }
 
diff --git a/hedera-node/hapi-utils/src/test/java/com/hedera/node/app/hapi/utils/ethereum/EthTxDataTest.java b/hedera-node/hapi-utils/src/test/java/com/hedera/node/app/hapi/utils/ethereum/EthTxDataTest.java
index b81b1248d945..cbede788248b 100644
--- a/hedera-node/hapi-utils/src/test/java/com/hedera/node/app/hapi/utils/ethereum/EthTxDataTest.java
+++ b/hedera-node/hapi-utils/src/test/java/com/hedera/node/app/hapi/utils/ethereum/EthTxDataTest.java
@@ -25,7 +25,6 @@
 import java.util.HexFormat;
 import java.util.List;
 import org.bouncycastle.asn1.sec.SECNamedCurves;
-import org.bouncycastle.util.BigIntegers;
 import org.hiero.base.utility.CommonUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -792,7 +791,7 @@ void bigPositiveValueWithDifferentTypes(final EthTransactionType type) {
     @Test
     void populateEthTxDataComparedToUnsignedByteArrayNoExtraByteAdded() {
         final var subject = EthTxData.populateEthTxData(HexFormat.of().parseHex(RAW_TX_TYPE_0_WITH_CHAIN_ID_11155111));
-        final byte[] passingChainId = BigIntegers.asUnsignedByteArray(BigInteger.valueOf(11155111L));
+        final byte[] passingChainId = EthTxData.asUnsignedByteArray(BigInteger.valueOf(11155111L));
         assertNotNull(subject);
         assertEquals(HexFormat.of().formatHex(subject.chainId()), HexFormat.of().formatHex(passingChainId));
     }
diff --git a/hedera-node/hedera-app/src/test/java/com/hedera/node/app/blocks/impl/BlockStreamManagerImplTest.java b/hedera-node/hedera-app/src/test/java/com/hedera/node/app/blocks/impl/BlockStreamManagerImplTest.java
index 50e1a449893a..58a2f4448c2a 100644
--- a/hedera-node/hedera-app/src/test/java/com/hedera/node/app/blocks/impl/BlockStreamManagerImplTest.java
+++ b/hedera-node/hedera-app/src/test/java/com/hedera/node/app/blocks/impl/BlockStreamManagerImplTest.java
@@ -104,7 +104,6 @@
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.Function;
-import org.bouncycastle.util.Arrays;
 import org.hiero.base.crypto.Hash;
 import org.hiero.base.crypto.test.fixtures.CryptoRandomUtils;
 import org.hiero.consensus.model.event.ConsensusEvent;
@@ -2185,7 +2184,7 @@ private PlatformState platformStateWithFreezeTime(@Nullable final Instant freeze
 
     private void mockRound(Instant timestamp, long roundNum) {
         given(round.getRoundNum()).willReturn(roundNum);
-        lenient().when(round.iterator()).thenReturn(new Arrays.Iterator<>(new ConsensusEvent[] {mockEvent}));
+        lenient().when(round.iterator()).thenReturn(List.of(mockEvent).iterator());
         lenient().when(round.getConsensusTimestamp()).thenReturn(timestamp);
     }
 
@@ -2217,7 +2216,7 @@ private void mockRoundWithTxnTimestamp(Instant timestamp, long roundNum) {
         txn.setConsensusTimestamp(timestamp);
         lenient()
                 .when(mockEvent.consensusTransactionIterator())
-                .thenReturn(new Arrays.Iterator<>(new ConsensusTransaction[] {txn}));
+                .thenReturn(List.<ConsensusTransaction>of(txn).iterator());
     }
 
     @Test