1 files changed, 1 insertions, 1 deletions
diff --git a/src/op.h b/src/op.h
index 973ba67f..2a705ca0 100644
--- a/src/op.h
+++ b/src/op.h
@@ -315,7 +315,7 @@ private:
   value_t calc_cons(scope_t& scope, ptr_op_t * locus, const int depth);
   value_t calc_seq(scope_t& scope, ptr_op_t * locus, const int depth);
 
-#if defined(HAVE_BOOST_SERIALIZATION)
+#if HAVE_BOOST_SERIALIZATION
 private:
   /** Serialization. */