diff --git a/lib/lib_internal.h b/lib/lib_internal.h
index 4c828fb381..37ebd0ffa7 100644
--- a/lib/lib_internal.h
+++ b/lib/lib_internal.h
@@ -158,7 +158,7 @@ extern int lib_lowvprintf(const char *src, va_list ap);
 
 /* Defined in lib_libwrite.c */
 
-extern ssize_t lib_fwrite(const void *ptr, size_t count, FAR FILE *stream);
+extern ssize_t lib_fwrite(FAR const void *ptr, size_t count, FAR FILE *stream);
 
 /* Defined in lib_libfread.c */