diff --git a/ChangeLog b/ChangeLog
index bc242004fe..65ae0562e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu May 21 20:27:07 2015  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* configure.in (RUBY_DTRACE_POSTPROCESS): cmp -b is GNU extension.
+	  darwin uses GNU cmp, and FreeBSD and Solaris are not.
+	  Note that accidentally equals to expected result.
+
 Thu May 21 18:00:19 2015  Koichi Sasada  <ko1@atdot.net>
 
 	* iseq.c: constify.
diff --git a/configure.in b/configure.in
index a967f3a0b5..c66590d469 100644
--- a/configure.in
+++ b/configure.in
@@ -649,7 +649,7 @@ _PROBES
 	    $DTRACE -G -s conftest_provider.d conftest.${ac_objext} 2>/dev/null &&
 	    :
 	}; then
-	    if cmp -b conftest.o conftest.${ac_objext}.save; then
+	    if cmp -s conftest.o conftest.${ac_objext}.save; then
 		rb_cv_prog_dtrace_g=yes
 	    else
 		rb_cv_prog_dtrace_g=rebuild