Amendment to the Spirit of Texas Bancshares, Inc. 2008 Stock Plan (dated May 21, 2015)

Exhibit 10.8

ST FINANCIAL GROUP, INC.

AMENDMENT TO 2008 STOCK PLAN

On May 21, 2015, the shareholders of ST Financial Group, Inc. (the “Company”) at a duly called annual meeting of shareholders approved an amendment to the ST Financial Group, Inc. 2008 Stock Plan (the “Plan”) to increase the number of shares of Company common stock available for issuance under the Plan from 2,600,000 to 3,500,000 shares.