diff --git a/docker/utils/utils.py b/docker/utils/utils.py
index bca88de5..4110017a 100644
--- a/docker/utils/utils.py
+++ b/docker/utils/utils.py
@@ -322,6 +322,9 @@ def parse_bytes(s):
     if len(s) == 0:
         s = 0
     else:
+        if s[-2:-1].isalpha() and s[-1].isalpha():
+            if (s[-1] == "b" or s[-1] == "B"):
+                s = s[:-1]
         units = BYTE_UNITS
         suffix = s[-1].lower()
 
diff --git a/tests/utils_test.py b/tests/utils_test.py
index 454a14e8..716cde55 100644
--- a/tests/utils_test.py
+++ b/tests/utils_test.py
@@ -6,7 +6,7 @@ from docker.client import Client
 from docker.errors import DockerException
 from docker.utils import (
     parse_repository_tag, parse_host, convert_filters, kwargs_from_env,
-    create_host_config, Ulimit, LogConfig
+    create_host_config, Ulimit, LogConfig, parse_bytes
 )
 from docker.utils.ports import build_port_bindings, split_port
 from docker.auth import resolve_authconfig
@@ -37,6 +37,12 @@ class UtilsTest(base.BaseTestCase):
         self.assertEqual(parse_repository_tag("url:5000/repo:tag"),
                          ("url:5000/repo", "tag"))
 
+    def test_parse_bytes(self):
+        self.assertEqual(parse_bytes("512MB"), (536870912))
+        self.assertEqual(parse_bytes("512M"), (536870912))
+        self.assertRaises(DockerException, parse_bytes, "512MK")
+        self.assertRaises(DockerException, parse_bytes, "512L")
+
     def test_parse_host(self):
         invalid_hosts = [
             '0.0.0.0',