1 files changed, 4 insertions, 0 deletions

diff --git a/plugins-root/check_icmp.c b/plugins-root/check_icmp.c
index 6a883a8..98891f0 100644
--- a/plugins-root/check_icmp.c
+++ b/plugins-root/check_icmp.c
@@ -467,10 +467,14 @@ main(int argc, char **argv)
                         unsigned short size;
                         switch(arg) {
                         case '4':
+                                if (address_family != -1)
+                                        crash("Multiple protocol versions not supported");
                                 address_family = AF_INET;
                                 break;
                         case '6':
 #ifdef USE_IPV6
+                                if (address_family != -1)
+                                        crash("Multiple protocol versions not supported");
                                 address_family = AF_INET6;
 #else
                                 usage (_("IPv6 support not available\n"));