diff --git a/firmware/common/file.h b/firmware/common/file.h
index 3233b40e87..58fb22d881 100644
--- a/firmware/common/file.h
+++ b/firmware/common/file.h
@@ -24,9 +24,11 @@
 #define SEEK_CUR 1
 #define SEEK_END 2
 
+#ifndef O_RDONLY
 #define O_RDONLY 0
 #define O_WRONLY 1
 #define O_RDWR   2
+#endif
 
 #ifndef SIMULATOR
 extern int open(char* pathname, int flags);