The invention relates to aminoacetonitrile compounds of the formula wherein m is 1, 2 or 3; R1 is C1-C4-alkyl, C1-C4-alkoxy, C1-C4-haloalkyl, C1-C4-haloalkoxy or halogen, whereby the substituents may respectively be identical or different, if m is greater than 1; and R2 is C1-C4-haloalkyl; and optionally enantiomers thereof; and the use of aminoacetonitrile compounds of formula I in the control of endoparasites, especially helminths, in warm-blooded productive livestock and domestic animals.