diff --git a/security-framework-sys/src/access_control.rs b/security-framework-sys/src/access_control.rs
index 07c21e4a..9089ab64 100644
--- a/security-framework-sys/src/access_control.rs
+++ b/security-framework-sys/src/access_control.rs
@@ -1,6 +1,7 @@
 use core_foundation_sys::base::CFOptionFlags;
 use core_foundation_sys::base::{CFAllocatorRef, CFTypeID, CFTypeRef};
 use core_foundation_sys::error::CFErrorRef;
+use core_foundation_sys::string::CFStringRef;
 
 use crate::base::SecAccessControlRef;
 
@@ -23,6 +24,15 @@ mod access_control_flags {
 
 pub use access_control_flags::*;
 
+extern "C" {
+    pub static kSecAttrAccessibleWhenUnlocked: CFStringRef;
+    pub static kSecAttrAccessibleAfterFirstUnlock: CFStringRef;
+    pub static kSecAttrAccessibleAlways: CFStringRef;
+    pub static kSecAttrAccessibleWhenUnlockedThisDeviceOnly: CFStringRef;
+    pub static kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly: CFStringRef;
+    pub static kSecAttrAccessibleAlwaysThisDeviceOnly: CFStringRef;
+}
+
 extern "C" {
     pub fn SecAccessControlGetTypeID() -> CFTypeID;