diff --git a/ChangeLog b/ChangeLog
index 100b6524ae..f0fe7f37a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Apr 21 23:19:00 2013  Charlie Somerville  <charlie@charliesomerville.com>
+
+	* configure.in: Revert using sigsetjmp by default due to performance
+	  problems on some systems (eg. older Linux)
+
 Sun Apr 21 21:35:00 2013  Charlie Somerville  <charlie@charliesomerville.com>
 
 	* configure.in: Use sigsetjmp by default so jumping out of signal
diff --git a/configure.in b/configure.in
index 5898895360..8fba7aa545 100644
--- a/configure.in
+++ b/configure.in
@@ -1745,12 +1745,12 @@ if test ${setjmp_prefix+set}; then
     if test "${setjmp_prefix}" && eval test '$ac_cv_func_'${setjmp_prefix}setjmp = no; then
 	AC_MSG_ERROR(${setjmp_prefix}setjmp is not available)
     fi
-elif test "$ac_cv_func_sigsetjmp" = yes; then
-    AS_CASE([$target_os],[solaris*|cygwin*],[setjmp_prefix=],[setjmp_prefix=sig])
 elif test "$ac_cv_func___builtin_setjmp" = yes; then
     setjmp_prefix=__builtin_
 elif test "$ac_cv_func__setjmp" = yes; then
     setjmp_prefix=_
+elif test "$ac_cv_func_sigsetjmp" = yes; then
+    AS_CASE([$target_os],[solaris*|cygwin*],[setjmp_prefix=],[setjmp_prefix=sig])
 else
     setjmp_prefix=
 fi
@@ -1760,7 +1760,7 @@ else
     unset setjmp_sigmask
 fi
 AC_MSG_RESULT(${setjmp_prefix}setjmp)
-AC_DEFINE_UNQUOTED([RUBY_SETJMP(env)], [${setjmp_prefix}setjmp(env${setjmp_sigmask+,1})])
+AC_DEFINE_UNQUOTED([RUBY_SETJMP(env)], [${setjmp_prefix}setjmp(env${setjmp_sigmask+,0})])
 AC_DEFINE_UNQUOTED([RUBY_LONGJMP(env,val)], [${setjmp_prefix}longjmp(env,val)])
 AC_DEFINE_UNQUOTED(RUBY_JMP_BUF, ${setjmp_sigmask+${setjmp_prefix}}jmp_buf)