diff --git a/types/sequelize/index.d.ts b/types/sequelize/index.d.ts
index 8c6622c1ab..0625a6406a 100644
--- a/types/sequelize/index.d.ts
+++ b/types/sequelize/index.d.ts
@@ -2890,9 +2890,12 @@ declare namespace sequelize {
         changed(): boolean | string[];
 
         /**
-         * Returns the previous value for key from `_previousDataValues`.
+         * If previous is called with a string, it will return the previous value for the key from `_previousDataValues`.
+         *
+         * If previous is called without an argument, it will return an object containing the previous keys and values that have changed.
          */
         previous(key: keyof TAttributes): any;
+        previous(): object;
 
         /**
          * Validate this instance, and if the validation passes, persist it to the database.
diff --git a/types/sequelize/sequelize-tests.ts b/types/sequelize/sequelize-tests.ts
index 702821ae25..0592a36df4 100644
--- a/types/sequelize/sequelize-tests.ts
+++ b/types/sequelize/sequelize-tests.ts
@@ -833,6 +833,7 @@ user.changed( 'name' );
 user.changed();
 
 user.previous( 'name' );
+user.previous();
 
 user.save().then( ( p ) => p );
 user.save( { fields : ['a'] } ).then( ( p ) => p );