consistently use 0-based counting of modems/slots
diff --git a/firmware/libboard/qmod/source/wwan_perst.c b/firmware/libboard/qmod/source/wwan_perst.c
index f16006f..b80fd55 100644
--- a/firmware/libboard/qmod/source/wwan_perst.c
+++ b/firmware/libboard/qmod/source/wwan_perst.c
@@ -45,11 +45,11 @@
 
 	switch (modem_nr) {
 #ifdef PIN_PERST1
-	case 1:
+	case 0:
 		return &perst1;
 #endif
 #ifdef PIN_PERST2
-	case 2:
+	case 1:
 		return &perst2;
 #endif
 	default: