diff --git a/MetadataCrypt.h b/MetadataCrypt.h
index e482765..06131ad 100644
--- a/MetadataCrypt.h
+++ b/MetadataCrypt.h
@@ -25,6 +25,7 @@
 namespace android {
 namespace vold {
 
+void defaultkey_precreate_dm_device();
 bool fscrypt_mount_metadata_encrypted(const std::string& block_device,
                                       const std::string& mount_point, bool needs_encrypt,
                                       bool should_format, const std::string& fs_type);