diff --git a/bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java b/bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java
index 9610a905c..0fdc03cee 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java
@@ -23,7 +23,6 @@ import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
-import org.briarproject.bramble.util.StringUtils;
 
 import java.io.IOException;
 import java.security.SecureRandom;
@@ -46,6 +45,9 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
+import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
+import static org.briarproject.bramble.util.StringUtils.macToBytes;
+import static org.briarproject.bramble.util.StringUtils.macToString;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -196,7 +198,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			address = getBluetoothAddress();
 			if (LOG.isLoggable(INFO))
 				LOG.info("Local address " + scrubMacAddress(address));
-			if (!StringUtils.isNullOrEmpty(address)) {
+			if (!isNullOrEmpty(address)) {
 				p.put(PROP_ADDRESS, address);
 				changed = true;
 			}
@@ -259,9 +261,9 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		// Try to connect to known devices in parallel
 		for (Entry<ContactId, TransportProperties> e : contacts.entrySet()) {
 			String address = e.getValue().get(PROP_ADDRESS);
-			if (StringUtils.isNullOrEmpty(address)) continue;
+			if (isNullOrEmpty(address)) continue;
 			String uuid = e.getValue().get(PROP_UUID);
-			if (StringUtils.isNullOrEmpty(uuid)) continue;
+			if (isNullOrEmpty(uuid)) continue;
 			ContactId c = e.getKey();
 			ioExecutor.execute(() -> {
 				if (!isRunning() || !shouldAllowContactConnections()) return;
@@ -312,9 +314,9 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (!isRunning() || !shouldAllowContactConnections()) return null;
 		if (!connectionLimiter.canOpenContactConnection()) return null;
 		String address = p.get(PROP_ADDRESS);
-		if (StringUtils.isNullOrEmpty(address)) return null;
+		if (isNullOrEmpty(address)) return null;
 		String uuid = p.get(PROP_UUID);
-		if (StringUtils.isNullOrEmpty(uuid)) return null;
+		if (isNullOrEmpty(uuid)) return null;
 		DuplexTransportConnection conn = connect(address, uuid);
 		if (conn == null) return null;
 		// TODO: Why don't we reset the backoff here?
@@ -347,7 +349,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		BdfList descriptor = new BdfList();
 		descriptor.add(TRANSPORT_ID_BLUETOOTH);
 		String address = getBluetoothAddress();
-		if (address != null) descriptor.add(StringUtils.macToBytes(address));
+		if (address != null) descriptor.add(macToBytes(address));
 		return new BluetoothKeyAgreementListener(descriptor, ss);
 	}
 
@@ -381,7 +383,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	private String parseAddress(BdfList descriptor) throws FormatException {
 		byte[] mac = descriptor.getRaw(1);
 		if (mac.length != 6) throw new FormatException();
-		return StringUtils.macToString(mac);
+		return macToString(mac);
 	}
 
 	@Override