diff --git a/common.h b/common.h
index cba4c86..ef2fe9f 100644
--- a/common.h
+++ b/common.h
@@ -126,4 +126,7 @@
 
 } UIParameters;
 
+// fopen a file, mounting volumes and making parent dirs as necessary.
+FILE* fopen_path(const char *path, const char *mode);
+
 #endif  // RECOVERY_COMMON_H