diff --git a/src/common/requests/download.cr b/src/common/requests/download.cr
index bb2ff34..ff06d74 100644
--- a/src/common/requests/download.cr
+++ b/src/common/requests/download.cr
@@ -12,7 +12,7 @@ class FileStorage::Request
 		def handle(filestoraged : FileStorage::Service, event : IPC::Event::Events)
 			user = filestoraged.get_logged_user event
 
-			raise Exception.new "unauthorized" if user.nil?
+			return Errors::Authorization.new @mid if user.nil?
 
 			# FIXME: Maybe this should be moved to FileStorage::Service
 			fd = event.connection.fd
@@ -35,4 +35,3 @@ class FileStorage::Response
 		end
 	end
 end
-
diff --git a/src/common/requests/errors.cr b/src/common/requests/errors.cr
index d4c3c01..5dd0ccd 100644
--- a/src/common/requests/errors.cr
+++ b/src/common/requests/errors.cr
@@ -7,8 +7,16 @@ class FileStorage::Errors
 	end
 	FileStorage.errors << GenericError
 
+	JSONIPC.request Authorization, 201 do
+		property mid    : String
+		property reason : String
+		def initialize(@mid, @reason = "authorization")
+		end
+	end
+	FileStorage.errors << Authorization
+
 	# When uploading a chunk already present in the DB.
-	JSONIPC.request ChunkAlreadyUploaded, 201 do
+	JSONIPC.request ChunkAlreadyUploaded, 202 do
 		property mid        : String
 		property reason     = "Chunk already present"
 		property filedigest : String
@@ -20,7 +28,7 @@ class FileStorage::Errors
 	FileStorage.errors << ChunkAlreadyUploaded
 
 	# You upload a chunk, but you are not the owner of the file.
-	JSONIPC.request ChunkUploadDenied, 202 do
+	JSONIPC.request ChunkUploadDenied, 203 do
 		property mid        : String
 		property reason     = "This file is not yours"
 		property filedigest : String
@@ -31,7 +39,7 @@ class FileStorage::Errors
 	FileStorage.errors << ChunkUploadDenied
 
 	# When uploading a file already present in the DB.
-	JSONIPC.request FileExists, 203 do
+	JSONIPC.request FileExists, 204 do
 		property mid        : String
 		property reason     = "file already present"
 		property filedigest : String
@@ -42,7 +50,7 @@ class FileStorage::Errors
 	FileStorage.errors << FileExists
 
 	# When transfering a chunk for an inexistent file.
-	JSONIPC.request FileDoesNotExist, 204 do
+	JSONIPC.request FileDoesNotExist, 205 do
 		property mid        : String
 		property reason     = "file does not exist"
 		property filedigest : String
diff --git a/src/common/requests/transfer.cr b/src/common/requests/transfer.cr
index 01c8808..b974a68 100644
--- a/src/common/requests/transfer.cr
+++ b/src/common/requests/transfer.cr
@@ -20,7 +20,7 @@ class FileStorage::Request
 		def handle(filestoraged : FileStorage::Service, event : IPC::Event::Events)
 			user = filestoraged.get_logged_user event
 
-			raise Exception.new "unauthorized" if user.nil?
+			return Errors::Authorization.new @mid if user.nil?
 
 			# FIXME: Maybe this should be moved to FileStorage::Service
 			fd = event.connection.fd
@@ -46,7 +46,7 @@ class FileStorage::Request
 		def handle(filestoraged : FileStorage::Service, event : IPC::Event::Events)
 			user = filestoraged.get_logged_user event
 
-			raise Exception.new "unauthorized" if user.nil?
+			return Errors::Authorization.new @mid if user.nil?
 
 			# FIXME: Maybe this should be moved to FileStorage::Service
 			fd = event.connection.fd
diff --git a/src/common/requests/upload.cr b/src/common/requests/upload.cr
index 81c9553..1136a66 100644
--- a/src/common/requests/upload.cr
+++ b/src/common/requests/upload.cr
@@ -10,7 +10,7 @@ class FileStorage::Request
 		def handle(filestoraged : FileStorage::Service, event : IPC::Event::Events)
 			user = filestoraged.get_logged_user event
 
-			raise Exception.new "unauthorized" if user.nil?
+			return Errors::Authorization.new @mid if user.nil?
 
 			# FIXME: Maybe this should be moved to FileStorage::Service
 			fd = event.connection.fd