diff --git a/cmatrix.c b/cmatrix.c
index 90284cb..7bca3f3 100644
--- a/cmatrix.c
+++ b/cmatrix.c
@@ -57,6 +57,10 @@
 #include <termio.h>
 #endif
 
+#ifdef __CYGWIN__
+#define TIOCSTI 0x5412
+#endif
+
 /* Matrix typedef */
 typedef struct cmatrix {
     int val;