diff --git a/src/fatfs/ffconf.h b/src/fatfs/ffconf.h
index 8e02e5b067..1a930c2bbf 100644
--- a/src/fatfs/ffconf.h
+++ b/src/fatfs/ffconf.h
@@ -59,7 +59,10 @@
 /* This option switches f_forward() function. (0:Disable or 1:Enable) */
 
 
+// FIXME: remove this, do not merge to stable without further discussion
+#ifndef FF_USE_STRFUNC
 #define FF_USE_STRFUNC	0
+#endif
 #define FF_PRINT_LLI	1
 #define FF_PRINT_FLOAT	1
 #define FF_STRF_ENCODE	3