diff --git a/vpnsetup.sh b/vpnsetup.sh
index d5da22d..76f9cf2 100755
--- a/vpnsetup.sh
+++ b/vpnsetup.sh
@@ -53,7 +53,8 @@ if [ "$(id -u)" != 0 ]; then
   exit 1
 fi
 
-if [ ! -f /sys/class/net/eth0/operstate ]; then
+eth0_state=$(cat /sys/class/net/eth0/operstate 2>/dev/null)
+if [ -z "$eth0_state" ] || [ "$eth0_state" = "down" ]; then
 cat 1>&2 <<'EOF'
 Network interface 'eth0' is not available. Aborting.
 
diff --git a/vpnsetup_centos.sh b/vpnsetup_centos.sh
index 626ae03..3704164 100755
--- a/vpnsetup_centos.sh
+++ b/vpnsetup_centos.sh
@@ -57,7 +57,8 @@ if [ "$(id -u)" != 0 ]; then
   exit 1
 fi
 
-if [ ! -f /sys/class/net/eth0/operstate ]; then
+eth0_state=$(cat /sys/class/net/eth0/operstate 2>/dev/null)
+if [ -z "$eth0_state" ] || [ "$eth0_state" = "down" ]; then
 cat 1>&2 <<'EOF'
 Network interface 'eth0' is not available. Aborting.