diff --git a/ChangeLog b/ChangeLog
index 2886c8fee8..800aebfd44 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed May 20 11:23:24 2015  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* vm_dump.c (rb_print_backtrace): return value of libexec's backtrace
+	  is size_t, so simply cast as int.
+
 Tue May 19 18:54:41 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* iseq.c (rb_iseq_compile_with_option): check source type, must be
diff --git a/vm_dump.c b/vm_dump.c
index 2c920b51d7..dc2f0a65d7 100644
--- a/vm_dump.c
+++ b/vm_dump.c
@@ -690,7 +690,7 @@ rb_print_backtrace(void)
 #if HAVE_BACKTRACE
 #define MAX_NATIVE_TRACE 1024
     static void *trace[MAX_NATIVE_TRACE];
-    int n = backtrace(trace, MAX_NATIVE_TRACE);
+    int n = (int)backtrace(trace, MAX_NATIVE_TRACE);
 #if defined(USE_ELF) && defined(HAVE_DLADDR)
     rb_dump_backtrace_with_lines(n, trace);
 #else