diff --git a/capnp/lib/capnp.pyx b/capnp/lib/capnp.pyx
index b69e0926d..ae8c4f1e4 100644
--- a/capnp/lib/capnp.pyx
+++ b/capnp/lib/capnp.pyx
@@ -1060,6 +1060,12 @@ cdef _to_dict(msg, bint verbose, bint ordered, bint encode_bytes_as_base64=False
         # encode the message as base64 and return utf-8 string
         return base64.b64encode(msg).decode('utf-8')
 
+    if msg_type is memoryview:
+        if encode_bytes_as_base64:
+            return base64.b64encode(bytes(msg)).decode('utf-8')
+        else:
+            return bytes(msg)
+
     return msg
 
 
diff --git a/setup.py b/setup.py
index 60c5ab7fe..ea4bc830a 100644
--- a/setup.py
+++ b/setup.py
@@ -222,6 +222,7 @@ def run(self):  # noqa: C901
             "*.capnp",
             "helpers/*.pxd",
             "helpers/*.h",
+            "includes/*.h",
             "includes/*.pxd",
             "lib/*.pxd",
             "lib/*.py",
diff --git a/test/test_blob_to_dict_base64.py b/test/test_blob_to_dict_base64.py
index c6f7a03b8..5e70f7ebf 100644
--- a/test/test_blob_to_dict_base64.py
+++ b/test/test_blob_to_dict_base64.py
@@ -1,5 +1,6 @@
 import os
 import capnp
+import base64
 import pytest
 
 this_dir = os.path.dirname(__file__)
@@ -14,7 +15,7 @@ def test_blob_to_dict(blob_schema):
     blob_value = b"hello world"
     blob = blob_schema.BlobTest(blob=blob_value)
     blob_dict = blob.to_dict(encode_bytes_as_base64=True)
-    assert blob_dict["blob"].tobytes() == blob_value
+    assert base64.b64decode(blob_dict["blob"]) == blob_value
     msg = blob_schema.BlobTest.new_message()
     msg.from_dict(blob_dict)
     assert blob.blob == blob_value