os2 patch by Jeff Rush
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
index e91c3cb..175f6eb 100644
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -50,6 +50,11 @@
 #define SIG_ERR ((RETSIGTYPE (*)())-1)
 #endif
 
+#if defined(PYOS_OS2)
+#define NSIG 12
+#include <process.h>
+#endif
+
 #ifndef NSIG
 #ifdef _SIGMAX
 #define NSIG (_SIGMAX + 1)	/* For QNX */