diff --git a/src/cryptography/hazmat/bindings/commoncrypto/cf.py b/src/cryptography/hazmat/bindings/commoncrypto/cf.py
index 6a6dbc4..77d2d7c 100644
--- a/src/cryptography/hazmat/bindings/commoncrypto/cf.py
+++ b/src/cryptography/hazmat/bindings/commoncrypto/cf.py
@@ -16,7 +16,7 @@
 
 typedef const void * CFAllocatorRef;
 const CFAllocatorRef kCFAllocatorDefault;
-typedef const void * CFDataRef;
+typedef ... *CFDataRef;
 typedef signed long long CFIndex;
 typedef ... *CFStringRef;
 typedef ... *CFArrayRef;