diff --git a/common/src/main/java/io/netty/util/internal/MacAddressUtil.java b/common/src/main/java/io/netty/util/internal/MacAddressUtil.java
index 41d4964c9e..4ac088750c 100644
--- a/common/src/main/java/io/netty/util/internal/MacAddressUtil.java
+++ b/common/src/main/java/io/netty/util/internal/MacAddressUtil.java
@@ -203,7 +203,8 @@ public final class MacAddressUtil {
     /**
      * @return positive - current is better, 0 - cannot tell from MAC addr, negative - candidate is better.
      */
-    private static int compareAddresses(byte[] current, byte[] candidate) {
+    // visible for testing
+    static int compareAddresses(byte[] current, byte[] candidate) {
         if (candidate == null || candidate.length < EUI48_MAC_ADDRESS_LENGTH) {
             return 1;
         }
@@ -227,20 +228,23 @@ public final class MacAddressUtil {
         }
 
         // Prefer globally unique address.
-        if (current.length == 0 || (current[0] & 2) == 0) {
-            if ((candidate[0] & 2) == 0) {
+        if ((candidate[0] & 2) == 0) {
+            if (current.length != 0 && (current[0] & 2) == 0) {
                 // Both current and candidate are globally unique addresses.
                 return 0;
             } else {
+                // Only candidate is globally unique.
+                return -1;
+            }
+        } else {
+            if (current.length != 0 && (current[0] & 2) == 0) {
                 // Only current is globally unique.
                 return 1;
+            } else {
+                // Both current and candidate are non-unique.
+                return 0;
             }
-        } else if ((candidate[0] & 2) == 0) {
-            // Only candidate is globally unique.
-            return -1;
         }
-        // Both current and candidate are non-unique.
-        return 0;
     }
 
     /**
diff --git a/common/src/test/java/io/netty/util/internal/MacAddressUtilTest.java b/common/src/test/java/io/netty/util/internal/MacAddressUtilTest.java
index 84d4e1229c..0af14f07ad 100644
--- a/common/src/test/java/io/netty/util/internal/MacAddressUtilTest.java
+++ b/common/src/test/java/io/netty/util/internal/MacAddressUtilTest.java
@@ -17,10 +17,57 @@ package io.netty.util.internal;
 
 import org.junit.Test;
 
+import static io.netty.util.internal.EmptyArrays.EMPTY_BYTES;
 import static io.netty.util.internal.MacAddressUtil.parseMAC;
 import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
 
 public class MacAddressUtilTest {
+    @Test
+    public void testCompareAddresses() {
+        // should not prefer empty address when candidate is not globally unique
+        assertEquals(
+                0,
+                MacAddressUtil.compareAddresses(
+                        EMPTY_BYTES,
+                        new byte[]{(byte) 0x52, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd}));
+
+        // only candidate is globally unique
+        assertEquals(
+                -1,
+                MacAddressUtil.compareAddresses(
+                        EMPTY_BYTES,
+                        new byte[]{(byte) 0x50, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd}));
+
+        // only candidate is globally unique
+        assertEquals(
+                -1,
+                MacAddressUtil.compareAddresses(
+                        new byte[]{(byte) 0x52, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd},
+                        new byte[]{(byte) 0x50, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd}));
+
+        // only current is globally unique
+        assertEquals(
+                1,
+                MacAddressUtil.compareAddresses(
+                        new byte[]{(byte) 0x52, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd},
+                        EMPTY_BYTES));
+
+        // only current is globally unique
+        assertEquals(
+                1,
+                MacAddressUtil.compareAddresses(
+                        new byte[]{(byte) 0x50, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd},
+                        new byte[]{(byte) 0x52, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd}));
+
+        // both are globally unique
+        assertEquals(
+                0,
+                MacAddressUtil.compareAddresses(
+                        new byte[]{(byte) 0x50, (byte) 0x54, (byte) 0x00, (byte) 0xf9, (byte) 0x32, (byte) 0xbd},
+                        new byte[]{(byte) 0x50, (byte) 0x55, (byte) 0x01, (byte) 0xfa, (byte) 0x33, (byte) 0xbe}));
+    }
+
     @Test
     public void testParseMacEUI48() {
         assertArrayEquals(new byte[]{0, (byte) 0xaa, 0x11, (byte) 0xbb, 0x22, (byte) 0xcc},