diff --git a/doc/gatt-api.txt b/doc/gatt-api.txt
index af0aa76..5042c54 100644
--- a/doc/gatt-api.txt
+++ b/doc/gatt-api.txt
@@ -79,13 +79,15 @@ Methods		array{byte} ReadValue(dict options)
 					  "mtu": Exchanged MTU (Server only)
 					  "device": Object Device (Server only)
 
-			Possible Errors: org.bluez.Error.Failed
+			Possible Errors: org.bluez.Error.Failed(string ecode)
 					 org.bluez.Error.InProgress
 					 org.bluez.Error.NotPermitted
 					 org.bluez.Error.NotAuthorized
 					 org.bluez.Error.InvalidOffset
 					 org.bluez.Error.NotSupported
 
+			Possible Error Code: string 0x80 - 0x9f
+
 		void WriteValue(array{byte} value, dict options)
 
 			Issues a request to write the value of the
@@ -105,13 +107,15 @@ Methods		array{byte} ReadValue(dict options)
 							       authorization
 							       request
 
-			Possible Errors: org.bluez.Error.Failed
+			Possible Errors: org.bluez.Error.Failed(string ecode)
 					 org.bluez.Error.InProgress
 					 org.bluez.Error.NotPermitted
 					 org.bluez.Error.InvalidValueLength
 					 org.bluez.Error.NotAuthorized
 					 org.bluez.Error.NotSupported
 
+			Possible Error Code: string 0x80 - 0x9f
+
 		fd, uint16 AcquireWrite(dict options) [optional]
 
 			Acquire file descriptor and MTU for writing. Only