diff --git a/src/microdot_asgi.py b/src/microdot_asgi.py
index 89b4be8..ecc9f31 100644
--- a/src/microdot_asgi.py
+++ b/src/microdot_asgi.py
@@ -59,8 +59,9 @@ class Microdot(BaseMicrodot):
         headers = NoCaseDict()
         content_length = 0
         for key, value in scope.get('headers', []):
-            headers[key] = value
-            if key.lower() == 'content-length':
+            key = key.decode().title()
+            headers[key] = value.decode()
+            if key == 'Content-Length':
                 content_length = int(value)
 
         if content_length and content_length <= Request.max_body_length:
diff --git a/tests/test_microdot_asgi.py b/tests/test_microdot_asgi.py
index 843927f..ae753cf 100644
--- a/tests/test_microdot_asgi.py
+++ b/tests/test_microdot_asgi.py
@@ -53,9 +53,9 @@ class TestMicrodotASGI(unittest.TestCase):
             'type': 'http',
             'path': '/foo/bar',
             'query_string': b'baz=1',
-            'headers': [('Authorization', 'Bearer 123'),
-                        ('Cookie', 'session=xyz'),
-                        ('Content-Length', 4)],
+            'headers': [(b'Authorization', b'Bearer 123'),
+                        (b'Cookie', b'session=xyz'),
+                        (b'Content-Length', b'4')],
             'client': ['1.2.3.4', 1234],
             'method': 'POST',
             'http_version': '1.1',
@@ -114,9 +114,9 @@ class TestMicrodotASGI(unittest.TestCase):
         scope = {
             'type': 'http',
             'path': '/foo/bar',
-            'headers': [('Authorization', 'Bearer 123'),
-                        ('Cookie', 'session=xyz'),
-                        ('Content-Length', 4)],
+            'headers': [(b'Authorization', b'Bearer 123'),
+                        (b'Cookie', b'session=xyz'),
+                        (b'Content-Length', b'4')],
             'client': ['1.2.3.4', 1234],
             'method': 'POST',
             'http_version': '1.1',