diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index f760764dc..e56eaafa4 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2011-04-21  Thomas Stalder <cygwinml@gmail.com>
+
+	* include/sys/poll.h: Include signal.h to get definition of sigset_t.
+
 2011-04-20  Christopher Faylor  <me.cygwin2011@cgf.cx>
 
 	* cygheap.cc (init_cygheap::close_ctty): Avoid closing console-cttys
diff --git a/winsup/cygwin/include/sys/poll.h b/winsup/cygwin/include/sys/poll.h
index a9d228b63..1a3a95b75 100644
--- a/winsup/cygwin/include/sys/poll.h
+++ b/winsup/cygwin/include/sys/poll.h
@@ -13,6 +13,7 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
+#include <signal.h>
 
 __BEGIN_DECLS