For decades, the Belgian personal income tax distinguished between income from foreign and domestic immovable property. Whereas for foreign immovable property the tax base attended to reflect real market values, income from domestic immovable property was determined on a lump sum basis, deducted from a market value of the immovable property in 1975 and subsequently indexed. As the lump sum estimation was substantially lower, the tax base for domestic immovable property income was reduced and hence investing in foreign immovable property was discouraged. Although already a decade ago the European Commission addressed Belgium on this distinction, it still took three convicting judgments of the European Court of Justice, before Belgium changed its legislation. Instead of leaving aside its outdated historical and heavily criticized lump sum estimation of domestic immovable property, the Belgian tax legislator opted to extend this regime and installed a similar historical evaluation for foreign immovable property referring to 1975. The new regime was installed as of tax year 2021. The following article describes the Belgian approach, explains why it was chosen and criticizes remaining issues and difficulties.