diff --git a/src/fileio.c b/src/fileio.c
index d4e12cbe277..a6e7fbb83d2 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -4165,7 +4165,7 @@ by calling `format-decode', which see.  */)
       Vdeactivate_mark = old_Vdeactivate_mark;
     }
   else
-    Vdeactivate_mark = Qt;
+    Fset (Qdeactivate_mark, Qt);
 
   emacs_close (fd);
   clear_unwind_protect (fd_index);
diff --git a/src/insdel.c b/src/insdel.c
index 80650be25ae..22c2bcccb82 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1846,7 +1846,7 @@ prepare_to_modify_buffer_1 (ptrdiff_t start, ptrdiff_t end,
       = call1 (Fsymbol_value (Qregion_extract_function), Qnil);
 
   signal_before_change (start, end, preserve_ptr);
-  Vdeactivate_mark = Qt;
+  Fset (Qdeactivate_mark, Qt);
 }
 
 /* Like above, but called when we know that the buffer text