diff --git a/fido2/ctap1.py b/fido2/ctap1.py
index 0d98c64..7f6adea 100644
--- a/fido2/ctap1.py
+++ b/fido2/ctap1.py
@@ -158,7 +158,7 @@ class SignatureData(bytes):
         super(SignatureData, self).__init__()
 
         reader = ByteBuffer(self)
-        self.user_presence = reader.unpack(">B")
+        self.user_presence = reader.unpack("B")
         self.counter = reader.unpack(">I")
         self.signature = reader.read()
 
diff --git a/fido2/ctap2.py b/fido2/ctap2.py
index e5ff46f..97b98e1 100644
--- a/fido2/ctap2.py
+++ b/fido2/ctap2.py
@@ -253,7 +253,7 @@ class AuthenticatorData(bytes):
 
         reader = ByteBuffer(self)
         self.rp_id_hash = reader.read(32)
-        self.flags = reader.unpack(">B")
+        self.flags = reader.unpack("B")
         self.counter = reader.unpack(">I")
         rest = reader.read()