diff --git a/fscrypt_uapi.h b/fscrypt_uapi.h
new file mode 100644
index 0000000..3999036
--- /dev/null
+++ b/fscrypt_uapi.h
@@ -0,0 +1,48 @@
+#ifndef _UAPI_LINUX_FSCRYPT_H
+#define _UAPI_LINUX_FSCRYPT_H
+
+// Definitions for FS_IOC_ADD_ENCRYPTION_KEY and FS_IOC_REMOVE_ENCRYPTION_KEY
+
+// TODO: switch to <linux/fscrypt.h> once it's in Bionic
+
+#ifndef FS_IOC_ADD_ENCRYPTION_KEY
+
+#include <linux/types.h>
+
+#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
+#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
+
+#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
+#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
+
+struct fscrypt_key_specifier {
+    __u32 type;
+    __u32 __reserved;
+    union {
+        __u8 __reserved[32];
+        __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
+        __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
+    } u;
+};
+
+struct fscrypt_add_key_arg {
+    struct fscrypt_key_specifier key_spec;
+    __u32 raw_size;
+    __u32 __reserved[9];
+    __u8 raw[];
+};
+
+struct fscrypt_remove_key_arg {
+    struct fscrypt_key_specifier key_spec;
+#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
+#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
+    __u32 removal_status_flags;
+    __u32 __reserved[5];
+};
+
+#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
+#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
+
+#endif /* FS_IOC_ADD_ENCRYPTION_KEY */
+
+#endif /* _UAPI_LINUX_FSCRYPT_H */