diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 8f8ed212e..1c44191d0 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,8 @@
+2012-10-26  Corinna Vinschen  <vinschen@redhat.com>
+
+	* libc/include/sys/signal.h (sigset_t): Don't define when building
+	for Cygwin.
+
 2012-10-24  Jeff Johnston  <jjohnstn@redhat.com>
 
 	* configure.in: Comment out the --enable-newlib-fp-hw option
diff --git a/newlib/libc/include/sys/signal.h b/newlib/libc/include/sys/signal.h
index 4e3be1ccf..3d6ba0831 100644
--- a/newlib/libc/include/sys/signal.h
+++ b/newlib/libc/include/sys/signal.h
@@ -12,7 +12,10 @@ extern "C" {
 
 /* #ifndef __STRICT_ANSI__*/
 
+/* Cygwin defines it's own sigset_t in include/cygwin/signal.h */
+#ifndef __CYGWIN__
 typedef unsigned long sigset_t;
+#endif
 
 #if defined(__rtems__)