diff --git a/src/file.h b/src/file.h
index 0128fa695..8d27dcdb7 100644
--- a/src/file.h
+++ b/src/file.h
@@ -39,7 +39,7 @@
 /// fileId of general file
 #define FILE_GENERAL   0
 /// convert model number 0..MAX_MODELS-1  int fileId
-#define FILE_MODEL(n) (1+n)
+#define FILE_MODEL(n) (1+(n))
 #define FILE_TMP      (1+16)
 
 bool EeFsOpen();