diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index b73a2d2..fa3296a 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -243,6 +243,7 @@
 	TPM2_CC_NV_DEFINE_SPACE	= 0x012a,
 	TPM2_CC_PCR_SETAUTHPOL	= 0x012C,
 	TPM2_CC_NV_WRITE	= 0x0137,
+	TPM2_CC_NV_WRITELOCK	= 0x0138,
 	TPM2_CC_DAM_RESET	= 0x0139,
 	TPM2_CC_DAM_PARAMETERS	= 0x013A,
 	TPM2_CC_NV_READ         = 0x014E,
@@ -572,4 +573,15 @@
  */
 u32 tpm2_get_random(struct udevice *dev, void *data, u32 count);
 
+/**
+ * Lock data in the TPM
+ *
+ * Once locked the data cannot be written until after a reboot
+ *
+ * @dev		TPM device
+ * @index	Index of data to lock
+ * @return code of the operation
+ */
+u32 tpm2_write_lock(struct udevice *dev, u32 index);
+
 #endif /* __TPM_V2_H */