diff --git a/serprog.h b/serprog.h
index 8d11772..b54aaea 100644
--- a/serprog.h
+++ b/serprog.h
@@ -22,3 +22,4 @@
 #define S_CMD_S_BUSTYPE		0x12	/* Set used bustype(s).				*/
 #define S_CMD_O_SPIOP		0x13	/* Perform SPI operation.			*/
 #define S_CMD_S_SPI_FREQ	0x14	/* Set SPI clock frequency			*/
+#define S_CMD_S_PIN_STATE	0x15	/* Enable/disable output drivers		*/