diff --git a/loopy/preprocess.py b/loopy/preprocess.py
index f2a3bba9f3b966c19881c8f959a118ca11bc3dd6..62e45b4af949760301bd536593408d08500973c6 100644
--- a/loopy/preprocess.py
+++ b/loopy/preprocess.py
@@ -463,7 +463,7 @@ def add_boostability_and_automatic_dependencies(kernel):
                         % (var, insn.id))
 
             if len(var_writers) == 1:
-                auto_deps.update(var_writers)
+                auto_deps.update(var_writers - set([insn.id]))
 
         # }}}