Constitution of the Republic of Malawi

Section 211

1. Any international agreement ratified by an Act of Parliament shall form part of the law of the Republic if so provided for in the Act of Parliament ratifying the agreement.
2. International agreements entered into before the commencement of this Constitution and binding on the Republic shall form part of the law of the Republic, unless Parliament subsequently provides otherwise or the agreement otherwise lapses.
3. Customary international law, unless inconsistent with this Constitution or an Act of Parliament, shall have continued application. 

 Labour Relations Act

Art. 2(2)

This Act shall be interpreted so as to give effect to the Constitution and the obligations of any international treaty, including any international labour conventions entered into or ratified by Malawi.