The invention relates to stabilizer systems, containing at least: a) a perchlorate salt; b) at least one or more compounds from the group consisting of carbamides, indole derivatives and enamines of formula (I), wherein n=1 or 2 and X=O or NR.sup.1; n=3 6 and X=O; R.sup.1=H, C.sub.1 C.sub.4-alkyl, C.sub.2 C.sub.6-alkenyl, C.sub.6 C.sub.10-aryl, C.sub.7 C.sub.18-alkaryl or C.sub.7 C.sub.18-aralkyl; R.sup.2 (if n=1)=C.sub.1 C.sub.22-alkyl, C.sub.2 C.sub.22-alkenyl or aryl, preferably phenyl, optionally substituted with up to 3 hydroxy, C.sub.1 C.sub.4-alkoxy or C.sub.1 C.sub.9-alkyl; or R.sup.2 (if n=2 6)=linear or branched C.sub.1-22-alkylene, optionally interrupted by one or more O or S atoms, wherein R.sup.2 (if n=3) can also be a C.sub.2 C.sub.3-alkyl trisubstituted isocyanurate; if X=NH R.sup.2 can also be H. Said stabilizer systems are suitable for stabilizing halogen-containing polymers, more particularly PVC.