diff --git a/linker/linker_utils.h b/linker/linker_utils.h
index 65ffbdc5..987eabd 100644
--- a/linker/linker_utils.h
+++ b/linker/linker_utils.h
@@ -22,6 +22,7 @@
 
 bool normalize_path(const char* path, std::string* normalized_path);
 bool file_is_in_dir(const std::string& file, const std::string& dir);
+bool file_is_under_dir(const std::string& file, const std::string& dir);
 bool parse_zip_path(const char* input_path, std::string* zip_path, std::string* entry_path);
 
 off64_t page_start(off64_t offset);