diff --git a/.travis.yml b/.travis.yml
index 2a667a2..a48f828 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,7 +10,8 @@ rvm:
   - 2.2
   - 2.3
   - 2.4.2
-  - 2.5.0
+  - 2.5.3
+  - 2.6.0
   - ruby-head
 
 matrix:
diff --git a/ext/debase_internals.h b/ext/debase_internals.h
index d6fc480..dcb2abe 100644
--- a/ext/debase_internals.h
+++ b/ext/debase_internals.h
@@ -2,12 +2,7 @@
 #define DEBASE_INTERNALS
 
 #include "ruby.h"
-#include "vm_core.h"
-#include "version.h"
-#include "iseq.h"
-#include "vm_insnhelper.h"
-#include "method.h"
-#include <ruby/debug.h>
+#include "ruby/debug.h"
 
 typedef struct rb_trace_arg_struct rb_trace_point_t;
 
diff --git a/lib/debase/version.rb b/lib/debase/version.rb
index 86243af..e833498 100644
--- a/lib/debase/version.rb
+++ b/lib/debase/version.rb
@@ -1,3 +1,3 @@
 module Debase
-  VERSION = "0.2.3.beta2" unless defined? VERSION
+  VERSION = "0.2.3.beta3" unless defined? VERSION
 end