diff --git a/types/index.d.ts b/types/index.d.ts
index 37901395c..86b3cfe0c 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -19,7 +19,7 @@ declare namespace dayjs {
 
   export type OptionType = FormatObject | string | string[]
 
-  export type UnitTypeShort = 'd' | 'M' | 'y' | 'h' | 'm' | 's' | 'ms'
+  export type UnitTypeShort = 'd' | 'D' | 'M' | 'y' | 'h' | 'm' | 's' | 'ms'
 
   export type UnitTypeLong = 'millisecond' | 'second' | 'minute' | 'hour' | 'day' | 'month' | 'year' | 'date'