Label

Element

Value

MFS® International Value Fund

Risk/Return:

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Supplement [Text Block]

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SUPPLEMENT TO PROSPECTUS

The date of this supplement is April 13, 2015.

MFS® International Value Fund

Risk/Return [Heading]

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MFS® International Value Fund

Strategy Narrative [Text Block]

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Effective immediately, the third paragraph in the sub-section entitled “Principal Investment Strategies” under the main heading "Summary of Key Information" is restated in its entirety as follows:

MFS focuses on investing the fund's assets in the stocks of companies it believes are undervalued compared to their intrinsic value (value companies). These companies may have stock prices that are higher relative to their earnings, dividends, assets, or other financial measures than companies generally considered value companies.