diff --git a/drivers/tee/optee/supplicant.c b/drivers/tee/optee/supplicant.c
index b1ea65b..c5726ec 100644
--- a/drivers/tee/optee/supplicant.c
+++ b/drivers/tee/optee/supplicant.c
@@ -82,8 +82,8 @@
 		cmd_shm_free(arg);
 		break;
 	case OPTEE_MSG_RPC_CMD_FS:
-		debug("OPTEE_MSG_RPC_CMD_FS not implemented\n");
-		arg->ret = TEE_ERROR_NOT_IMPLEMENTED;
+		debug("REE FS storage isn't available\n");
+		arg->ret = TEE_ERROR_STORAGE_NOT_AVAILABLE;
 		break;
 	case OPTEE_MSG_RPC_CMD_RPMB:
 		optee_suppl_cmd_rpmb(dev, arg);
diff --git a/include/tee.h b/include/tee.h
index 98b1c9c..edd9f9b 100644
--- a/include/tee.h
+++ b/include/tee.h
@@ -34,6 +34,7 @@
  * struct tee_version_data::gen_caps
  */
 #define TEE_SUCCESS			0x00000000
+#define TEE_ERROR_STORAGE_NOT_AVAILABLE	0xf0100003
 #define TEE_ERROR_GENERIC		0xffff0000
 #define TEE_ERROR_BAD_PARAMETERS	0xffff0006
 #define TEE_ERROR_ITEM_NOT_FOUND	0xffff0008