diff --git a/.dir-locals.el b/.dir-locals.el
index 6dbdc9aed..1ac9c993d 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -1,6 +1,7 @@
-((nil . ((indent-tabs-mode . nil)
-         (fill-column . 79)))
- (c-mode . ((c-file-style . "gnu")))
- (c++-mode . ((c-file-style . "gnu")))
+((c-mode . ((indent-tabs-mode . nil)
+            (c-file-style . "gnu")))
+ (c++-mode . ((indent-tabs-mode . nil)
+              (c-file-style . "gnu")))
  (makefile-mode . ((indent-tabs-mode . t)))
- (octave-mode . ((octave-block-offset . 4))))
+ (octave-mode . ((indent-tabs-mode . nil)
+                 (octave-block-offset . 4))))