jpype - diactric signs cause UnicodeDecodeError

Question

I've recently started using jpype and it worked nice so far but when I tried to pass a string with polish diacritic sings (ą,ć,ó - stuff like that) as a parameter it throws UnicodeDecodeError.

Even java.lang.System.out.println("Mąka") throws UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 1: ordinal not in range(128)

Is there a way around it? Using diacritic signs is crucial for this app....