diff --git a/src/isdn/main.c b/src/isdn/main.c
index 3c5273f..d211224 100644
--- a/src/isdn/main.c
+++ b/src/isdn/main.c
@@ -126,9 +126,9 @@ static void print_help()
 	printf("        Give a delay in milliseconds. This is required for modem/fax. Audio\n");
 	printf("        toward ISDN interface is buffered with the given delay.\n");
 	printf("	This feature alters dejittering strategy.\n");
-	printf("--aocd\n");
+	printf(" --aocd\n");
 	printf("        Send AOC-D charging information\n");
-	printf("--aocs\n");
+	printf(" --aocs\n");
 	printf("        Send AOC-S charging information\n");
 	printf(" -T --local-tones german | oldgerman | american\n");
 	printf("        Send locally generated tones, if not provided by remote interface.\n");