diff --git a/custom/conf/app.example.ini b/custom/conf/app.example.ini
index 1d19a343804f..d86092350021 100644
--- a/custom/conf/app.example.ini
+++ b/custom/conf/app.example.ini
@@ -1617,7 +1617,7 @@ PATH =
 ;ENABLED = true
 ;;
 ;; Comma-separated list of allowed file extensions (`.zip`), mime types (`text/plain`) or wildcard type (`image/*`, `audio/*`, `video/*`). Empty value or `*/*` allows all types.
-;ALLOWED_TYPES = .docx,.gif,.gz,.jpeg,.jpg,.log,.pdf,.png,.pptx,.txt,.xlsx,.zip
+;ALLOWED_TYPES = .docx,.gif,.gz,.jpeg,.jpg,.mp4,.log,.pdf,.png,.pptx,.txt,.xlsx,.zip
 ;;
 ;; Max size of each file. Defaults to 4MB
 ;MAX_SIZE = 4
diff --git a/docs/content/doc/advanced/config-cheat-sheet.en-us.md b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
index 90117efb24de..02a61fe44576 100644
--- a/docs/content/doc/advanced/config-cheat-sheet.en-us.md
+++ b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
@@ -731,7 +731,7 @@ Default templates for project boards:
 ## Issue and pull request attachments (`attachment`)
 
 - `ENABLED`: **true**: Whether issue and pull request attachments are enabled.
-- `ALLOWED_TYPES`: **.docx,.gif,.gz,.jpeg,.jpg,.log,.pdf,.png,.pptx,.txt,.xlsx,.zip**: Comma-separated list of allowed file extensions (`.zip`), mime types (`text/plain`) or wildcard type (`image/*`, `audio/*`, `video/*`). Empty value or `*/*` allows all types.
+- `ALLOWED_TYPES`: **.docx,.gif,.gz,.jpeg,.jpg,mp4,.log,.pdf,.png,.pptx,.txt,.xlsx,.zip**: Comma-separated list of allowed file extensions (`.zip`), mime types (`text/plain`) or wildcard type (`image/*`, `audio/*`, `video/*`). Empty value or `*/*` allows all types.
 - `MAX_SIZE`: **4**: Maximum size (MB).
 - `MAX_FILES`: **5**: Maximum number of attachments that can be uploaded at once.
 - `STORAGE_TYPE`: **local**: Storage type for attachments, `local` for local disk or `minio` for s3 compatible object storage service, default is `local` or other name defined with `[storage.xxx]`
diff --git a/modules/setting/attachment.go b/modules/setting/attachment.go
index 98c4be94e9cd..409c2b87e54c 100644
--- a/modules/setting/attachment.go
+++ b/modules/setting/attachment.go
@@ -29,7 +29,7 @@ func newAttachmentService() {
 
 	Attachment.Storage = getStorage("attachments", storageType, sec)
 
-	Attachment.AllowedTypes = sec.Key("ALLOWED_TYPES").MustString(".docx,.gif,.gz,.jpeg,.jpg,.log,.pdf,.png,.pptx,.txt,.xlsx,.zip")
+	Attachment.AllowedTypes = sec.Key("ALLOWED_TYPES").MustString(".docx,.gif,.gz,.jpeg,.jpg,.mp4,.log,.pdf,.png,.pptx,.txt,.xlsx,.zip")
 	Attachment.MaxSize = sec.Key("MAX_SIZE").MustInt64(4)
 	Attachment.MaxFiles = sec.Key("MAX_FILES").MustInt(5)
 	Attachment.Enabled = sec.Key("ENABLED").MustBool(true)