diff --git a/icnsutil/PackBytes.py b/icnsutil/PackBytes.py
index 8917d37..4d1f5c9 100644
--- a/icnsutil/PackBytes.py
+++ b/icnsutil/PackBytes.py
@@ -22,15 +22,18 @@ def pack(data: List[int]) -> bytes:
             flush_buf()
             # repeating
             c = 3
-            while (i + c) < len(data) and data[i + c] == x:
+            while (i + c) < end and data[i + c] == x:
                 c += 1
             i += c
             while c > 130:  # max number of copies encodable in compression
                 ret.append(0xFF)
                 ret.append(x)
                 c -= 130
-            ret.append(c + 0x7D)  # 0x80 - 3
-            ret.append(x)
+            if c > 2:
+                ret.append(c + 0x7D)  # 0x80 - 3
+                ret.append(x)
+            else:
+                i -= c
         else:
             buf.append(x)
             if len(buf) > 127:
diff --git a/tests/test_icnsutil.py b/tests/test_icnsutil.py
index 24020a8..93ee869 100644
--- a/tests/test_icnsutil.py
+++ b/tests/test_icnsutil.py
@@ -376,6 +376,10 @@ class TestPackBytes(unittest.TestCase):
         self.assertEqual(d, b'\x01\x01\x02\xff\x03\x81\x03\x01\x04\x05')
         d = PackBytes.pack(b'\x00' * 223 + b'\x01' * 153)
         self.assertEqual(d, b'\xff\x00\xda\x00\xff\x01\x94\x01')
+        d = PackBytes.pack(b'\x13' * 131)
+        self.assertEqual(d, b'\xff\x13\x00\x13')
+        d = PackBytes.pack(b'\x13' * 132)
+        self.assertEqual(d, b'\xff\x13\x01\x13\x13')
 
     def test_unpack(self):
         d = PackBytes.unpack(b'\xff\x00\xff\x00\xff\x00\xf9\x00')
@@ -386,6 +390,8 @@ class TestPackBytes(unittest.TestCase):
         self.assertListEqual(d, [1, 2] + [3] * 134 + [4, 5])
         d = PackBytes.unpack(b'\xff\x00\xda\x00\xff\x01\x94\x01')
         self.assertListEqual(d, [0] * 223 + [1] * 153)
+        d = PackBytes.unpack(b'\xff\x13\x00\x13')
+        self.assertListEqual(d, [19] * 131)
 
     def test_get_size(self):
         for d in [b'\xff\x00\xff\x00\xff\x00\xf9\x00',