diff --git a/ChangeLog b/ChangeLog
index 8acead194e..3dc56f74d7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jan 16 17:20:33 2015  Koichi Sasada  <ko1@atdot.net>
+
+	vm.c, vm_core.h: constify VM_CF_LEP, VM_CF_PREV_EP, VM_CF_BLOCK_PTR
+	and rb_vm_control_frame_block_ptr.
+
 Fri Jan 16 15:41:21 2015  Aaron Patterson <aaron@tenderlovemaking.com>
 
 	* ext/psych/lib/psych.rb: bump version
diff --git a/vm.c b/vm.c
index 80b3bbe5aa..3aaf1ea483 100644
--- a/vm.c
+++ b/vm.c
@@ -55,26 +55,26 @@ rb_vm_ep_local_ep(VALUE *ep)
 }
 
 static inline VALUE *
-VM_CF_LEP(rb_control_frame_t *cfp)
+VM_CF_LEP(const rb_control_frame_t * const cfp)
 {
     return VM_EP_LEP(cfp->ep);
 }
 
 static inline VALUE *
-VM_CF_PREV_EP(rb_control_frame_t * cfp)
+VM_CF_PREV_EP(const rb_control_frame_t * const cfp)
 {
     return VM_EP_PREV_EP(cfp->ep);
 }
 
 static inline rb_block_t *
-VM_CF_BLOCK_PTR(rb_control_frame_t *cfp)
+VM_CF_BLOCK_PTR(const rb_control_frame_t * const cfp)
 {
     VALUE *ep = VM_CF_LEP(cfp);
     return VM_EP_BLOCK_PTR(ep);
 }
 
 rb_block_t *
-rb_vm_control_frame_block_ptr(rb_control_frame_t *cfp)
+rb_vm_control_frame_block_ptr(const rb_control_frame_t *cfp)
 {
     return VM_CF_BLOCK_PTR(cfp);
 }
diff --git a/vm_core.h b/vm_core.h
index 809da4e86f..b014383339 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -902,7 +902,7 @@ typedef rb_control_frame_t *
 #define VM_EP_LEP_P(ep)     VM_ENVVAL_BLOCK_PTR_P((ep)[0])
 
 VALUE *rb_vm_ep_local_ep(VALUE *ep);
-rb_block_t *rb_vm_control_frame_block_ptr(rb_control_frame_t *cfp);
+rb_block_t *rb_vm_control_frame_block_ptr(const rb_control_frame_t *cfp);
 
 #define RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp) ((cfp)+1)
 #define RUBY_VM_NEXT_CONTROL_FRAME(cfp) ((cfp)-1)