diff --git a/lib/dialects/mariadb/data-types.js b/lib/dialects/mariadb/data-types.js
index aa4098535631..769af6bfc8b2 100644
--- a/lib/dialects/mariadb/data-types.js
+++ b/lib/dialects/mariadb/data-types.js
@@ -54,8 +54,12 @@ module.exports = BaseTypes => {
       return this._length ? `DATETIME(${this._length})` : 'DATETIME';
     }
     _stringify(date, options) {
-      date = this._applyTimezone(date, options);
-      return date.format('YYYY-MM-DD HH:mm:ss.SSS');
+      if(_.isDate(date)){
+        date = this._applyTimezone(date, options);
+        return date.format('YYYY-MM-DD HH:mm:ss.SSS');
+      }
+
+      return date;
     }
     static parse(value, options) {
       value = value.string();
diff --git a/lib/dialects/mysql/data-types.js b/lib/dialects/mysql/data-types.js
index c0beec964da9..25abe7f71e75 100644
--- a/lib/dialects/mysql/data-types.js
+++ b/lib/dialects/mysql/data-types.js
@@ -53,12 +53,16 @@ module.exports = BaseTypes => {
       return this._length ? `DATETIME(${this._length})` : 'DATETIME';
     }
     _stringify(date, options) {
-      date = this._applyTimezone(date, options);
-      // Fractional DATETIMEs only supported on MySQL 5.6.4+
-      if (this._length) {
-        return date.format('YYYY-MM-DD HH:mm:ss.SSS');
+      if(_.isDate(date)){
+        date = this._applyTimezone(date, options);
+        // Fractional DATETIMEs only supported on MySQL 5.6.4+
+        if (this._length) {
+          return date.format('YYYY-MM-DD HH:mm:ss.SSS');
+        }
+        return date.format('YYYY-MM-DD HH:mm:ss');
       }
-      return date.format('YYYY-MM-DD HH:mm:ss');
+
+      return date;
     }
     static parse(value, options) {
       value = value.string();