diff --git a/lib/migration.js b/lib/migration.js
index 6e69174a..95826f9a 100644
--- a/lib/migration.js
+++ b/lib/migration.js
@@ -628,13 +628,19 @@ function mixinMigration(MySQL, mysql) {
       if (pks.length === 1) {
         const idName = this.idName(model);
         const idProp = this.getModelDefinition(model).properties[idName];
-        if (idProp.generated) {
+        const idColumnType = this.columnDataType(model, idName);
+        if (idProp.generated && (
+          idColumnType === 'TINYINT' ||
+          idColumnType === 'SMALLINT' ||
+          idColumnType === 'MEDIUMINT' ||
+          idColumnType === 'INT' ||
+          idColumnType === 'BIGINT')) {
           sql.push(self.columnEscaped(model, idName) + ' ' +
-            self.buildColumnDefinition(model, idName) + ' AUTO_INCREMENT PRIMARY KEY');
+          self.buildColumnDefinition(model, idName) + ' AUTO_INCREMENT PRIMARY KEY');
         } else {
           idProp.nullable = false;
           sql.push(self.columnEscaped(model, idName) + ' ' +
-            self.buildColumnDefinition(model, idName) + ' PRIMARY KEY');
+          self.buildColumnDefinition(model, idName) + ' PRIMARY KEY');
         }
       }
       Object.keys(definition.properties).forEach(function(prop) {