diff --git a/cryptfs.h b/cryptfs.h
index 9b5eae7..d805df7 100644
--- a/cryptfs.h
+++ b/cryptfs.h
@@ -74,7 +74,7 @@
 void cryptfs_clear_password(void);
 int cryptfs_isConvertibleToFBE(void);
 
-uint32_t cryptfs_get_keysize();
+size_t cryptfs_get_keysize();
 const char* cryptfs_get_crypto_name();
 
 #endif /* ANDROID_VOLD_CRYPTFS_H */