diff --git a/include/image.h b/include/image.h
index 4c278c7..621abf6 100644
--- a/include/image.h
+++ b/include/image.h
@@ -153,6 +153,7 @@
 	IH_OS_PLAN9,			/* Plan 9	*/
 	IH_OS_OPENRTOS,		/* OpenRTOS	*/
 	IH_OS_ARM_TRUSTED_FIRMWARE,     /* ARM Trusted Firmware */
+	IH_OS_TEE,			/* Trusted Execution Environment */
 
 	IH_OS_COUNT,
 };