The present disclosure relates to a gas hydrate inhibitor composition, comprising A) a compound according to formula (1) wherein R1 is an alkyl group having from 1 to 5 carbon atoms; R2 is hydrogen or an alkyl group having from 1 to 5 carbon atoms; R3 is present or not as hydrogen and organic moieties having from 1 to 20 carbon atoms; R4 is selected from —(CH2)t—, —[CH2—CHR6)t]—, —(CH2—CHR6O)u—(CH2)t— and combinations thereof; R5 is an alkyl or alkenyl group having 4 to 22 carbon atoms; R6 is hydrogen or an alkyl group having from 1 to 4 carbon atoms; R7 is hydrogen or an alkyl group having from 1 to 4 carbon atoms; R8 is present or not as hydrogen or organic moieties having from 1 to 20 carbon atoms; t is 2, 3 or 4; u is an integer between 0 and 100; n is 0 or 1 m is 0 or 2 o is 0 or 2, p is 0 or 1 X− is an anion, and a synergistic cationic surfactant which is selected from quaternary benzyl ammonium salts having besides the benzyl group at least one C8-C18-alkyl group bound to the nitrogen atom.