3 files changed, 9 insertions, 8 deletions
diff --git a/vm.c b/vm.c
index 8551b0dc0e..750c756808 100644
--- a/vm.c
+++ b/vm.c
@@ -231,7 +231,7 @@ vm_set_main_stack(rb_thread_t *th, VALUE iseqval)
 }
 
 rb_control_frame_t *
-rb_vm_get_binding_creatable_next_cfp(rb_thread_t *th, const rb_control_frame_t *cfp)
+rb_vm_get_binding_creatable_next_cfp(const rb_thread_t *th, const rb_control_frame_t *cfp)
 {
     while (!RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(th, cfp)) {
 	if (cfp->iseq) {
@@ -243,7 +243,7 @@ rb_vm_get_binding_creatable_next_cfp(rb_thread_t *th, const rb_control_frame_t *
 }
 
 rb_control_frame_t *
-rb_vm_get_ruby_level_next_cfp(rb_thread_t *th, const rb_control_frame_t *cfp)
+rb_vm_get_ruby_level_next_cfp(const rb_thread_t *th, const rb_control_frame_t *cfp)
 {
     while (!RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(th, cfp)) {
 	if (RUBY_VM_NORMAL_ISEQ_P(cfp->iseq)) {
@@ -255,17 +255,17 @@ rb_vm_get_ruby_level_next_cfp(rb_thread_t *th, const rb_control_frame_t *cfp)
 }
 
 static rb_control_frame_t *
-vm_get_ruby_level_caller_cfp(rb_thread_t *th, rb_control_frame_t *cfp)
+vm_get_ruby_level_caller_cfp(const rb_thread_t *th, const rb_control_frame_t *cfp)
 {
     if (RUBY_VM_NORMAL_ISEQ_P(cfp->iseq)) {
-	return cfp;
+	return (rb_control_frame_t *)cfp;
     }
 
     cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
 
     while (!RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(th, cfp)) {
 	if (RUBY_VM_NORMAL_ISEQ_P(cfp->iseq)) {
-	    return cfp;
+	    return (rb_control_frame_t *)cfp;
 	}
 
 	if ((cfp->flag & VM_FRAME_FLAG_PASSED) == 0) {
diff --git a/vm_core.h b/vm_core.h
index 9ab23b2087..93163098e2 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -988,8 +988,8 @@ rb_vm_living_threads_remove(rb_vm_t *vm, rb_thread_t *th)
 
 int ruby_thread_has_gvl_p(void);
 typedef int rb_backtrace_iter_func(void *, VALUE, int, VALUE);
-rb_control_frame_t *rb_vm_get_ruby_level_next_cfp(rb_thread_t *th, const rb_control_frame_t *cfp);
-rb_control_frame_t *rb_vm_get_binding_creatable_next_cfp(rb_thread_t *th, const rb_control_frame_t *cfp);
+rb_control_frame_t *rb_vm_get_ruby_level_next_cfp(const rb_thread_t *th, const rb_control_frame_t *cfp);
+rb_control_frame_t *rb_vm_get_binding_creatable_next_cfp(const rb_thread_t *th, const rb_control_frame_t *cfp);
 int rb_vm_get_sourceline(const rb_control_frame_t *);
 VALUE rb_name_err_mesg_new(VALUE obj, VALUE mesg, VALUE recv, VALUE method);
 void rb_vm_stack_to_heap(rb_thread_t *th);
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index d5314c7b67..b875e2c627 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -22,7 +22,8 @@
 #define INLINE inline
 #endif
 
-static rb_control_frame_t *vm_get_ruby_level_caller_cfp(rb_thread_t *th, rb_control_frame_t *cfp);
+static rb_control_frame_t *
+vm_get_ruby_level_caller_cfp(const rb_thread_t *th, const rb_control_frame_t *cfp);
 
 VALUE
 ruby_vm_sysstack_error_copy(void)