diff --git a/library/src/main/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtils.java b/library/src/main/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtils.java
index c872f82..0f245d4 100644
--- a/library/src/main/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtils.java
+++ b/library/src/main/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtils.java
@@ -58,14 +58,14 @@ public static List<AdRecord> parseScanRecordAsList(final byte[] scanRecord) {
 
         int index = 0;
         while (index < scanRecord.length) {
-            final int length = scanRecord[index++];
+            final int length = scanRecord[index++] & 0xFF;
             //Done once we run out of records
-            if (length == 0) break;
+            if (length < 1) break;
 
             final int type = ByteUtils.getIntFromByte(scanRecord[index]);
 
             //Done if our record isn't a valid type
-            if (type == 0) break;
+            if (type < 1) break;
 
             final byte[] data = Arrays.copyOfRange(scanRecord, index + 1, index + length);
 
@@ -84,14 +84,14 @@ public static Map<Integer, AdRecord> parseScanRecordAsMap(final byte[] scanRecor
 
         int index = 0;
         while (index < scanRecord.length) {
-            final int length = scanRecord[index++];
+            final int length = scanRecord[index++] & 0xFF;
             //Done once we run out of records
-            if (length == 0) break;
+            if (length < 1) break;
 
             final int type = ByteUtils.getIntFromByte(scanRecord[index]);
 
             //Done if our record isn't a valid type
-            if (type == 0) break;
+            if (type < 1) break;
 
             final byte[] data = Arrays.copyOfRange(scanRecord, index + 1, index + length);
 
@@ -109,14 +109,14 @@ public static SparseArray<AdRecord> parseScanRecordAsSparseArray(final byte[] sc
 
         int index = 0;
         while (index < scanRecord.length) {
-            final int length = scanRecord[index++];
+            final int length = scanRecord[index++] & 0xFF;
             //Done once we run out of records
-            if (length == 0) break;
+            if (length < 1) break;
 
             final int type = ByteUtils.getIntFromByte(scanRecord[index]);
 
             //Done if our record isn't a valid type
-            if (type == 0) break;
+            if (type < 1) break;
 
             final byte[] data = Arrays.copyOfRange(scanRecord, index + 1, index + length);
 
diff --git a/library/src/test/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtilsTest.java b/library/src/test/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtilsTest.java
index d528dd8..35b7afb 100644
--- a/library/src/test/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtilsTest.java
+++ b/library/src/test/java/uk/co/alt236/bluetoothlelib/util/AdRecordUtilsTest.java
@@ -1,23 +1,21 @@
 package uk.co.alt236.bluetoothlelib.util;
 
-import junit.framework.TestCase;
-
 import java.util.List;
 import java.util.Map;
-
+import junit.framework.TestCase;
 import uk.co.alt236.bluetoothlelib.device.adrecord.AdRecord;
 
 /**
- *
+ * Advertisement records related tests.
  */
 public class AdRecordUtilsTest extends TestCase {
-    private static final byte[] NON_IBEACON =
-            {2, 1, 26, 11, -1, 76, 0, 9, 6, 3, -32, -64, -88,
-                    1, 98, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-                    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-                    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    private static final byte[] NON_IBEACON = {
+        2, 1, 26, 11, -1, 76, 0, 9, 6, 3, -32, -64, -88, 1, 98, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0
+    };
 
-    public void testParseScanRecordAsList() throws Exception {
+    public void testParseScanRecordAsList() {
         final List<AdRecord> adRecords = AdRecordUtils.parseScanRecordAsList(NON_IBEACON);
         assertNotNull(adRecords);
         assertEquals(2, adRecords.size());
@@ -31,7 +29,7 @@ public void testParseScanRecordAsList() throws Exception {
         assertEquals(11, adRecords.get(1).getLength());
     }
 
-    public void testParseScanRecordAsMap() throws Exception {
+    public void testParseScanRecordAsMap() {
         final Map<Integer, AdRecord> adRecords = AdRecordUtils.parseScanRecordAsMap(NON_IBEACON);
         assertNotNull(adRecords);
         assertEquals(2, adRecords.size());
@@ -45,7 +43,27 @@ public void testParseScanRecordAsMap() throws Exception {
         assertEquals(11, adRecords.get(type).getLength());
     }
 
-    public void testParseScanRecordAsSparseArray() throws Exception {
+    /**
+     * Test negative record lengths. In Java all primitive types are signed, and we could receive
+     * a negative length in the record. Thus, we always have to convert it into unsigned.
+     */
+    public void testNegativeRecordLength() {
+        // (byte)0x80 & 0xFF = 170. In Java (byte)0x80 = -128.
+        Map<Integer, AdRecord> adRecords =
+            AdRecordUtils.parseScanRecordAsMap(new byte[] { -128, 1, 0 });
+        assertNotNull(adRecords);
+        assertEquals(1, adRecords.size());
+        assertEquals(128, adRecords.get(1).getLength());
+
+        // (byte)0xAA & 0xFF = 170. In Java (byte)0xAA = -86.
+        adRecords =
+            AdRecordUtils.parseScanRecordAsMap(new byte[] { -86, 1, 0 });
+        assertNotNull(adRecords);
+        assertEquals(1, adRecords.size());
+        assertEquals(170, adRecords.get(1).getLength());
+    }
+
+    public void testParseScanRecordAsSparseArray() {
         //
         // Cannot be tested here as it relies on Android code...
         //