diff --git a/res/miracle-utils.sh b/res/miracle-utils.sh
index e77fff0..12186c5 100755
--- a/res/miracle-utils.sh
+++ b/res/miracle-utils.sh
@@ -52,7 +52,7 @@ function find_wireless_connected_network_interfaces {
 #
 function find_physical_for_network_interface {
    PHY_INDEX=$(iw dev $1 info | grep wiphy | awk '{print $2}')
-   if [ -n $PHY_INDEX ]
+   if [ -n "$PHY_INDEX" ]
    then
       echo phy$PHY_INDEX
    fi
@@ -65,6 +65,12 @@ function search_p2p_capabilities {
    WI_DEVICE=$1
    PHY_DEVICE=$(find_physical_for_network_interface $WI_DEVICE)
 
+   if [ -z "$PHY_DEVICE" ]
+   then
+      echo "cannot find physical device for $WI_DEVICE"
+      return
+   fi
+
    if iw phy $PHY_DEVICE info | grep -Pzo "(?s)Supported interface modes.*Supported commands" | grep "P2P" &> /dev/null
    then
       echo $WI_DEVICE supports P2P
diff --git a/res/test-hardware-capabilities.sh b/res/test-hardware-capabilities.sh
index f3bab45..1e227f5 100755
--- a/res/test-hardware-capabilities.sh
+++ b/res/test-hardware-capabilities.sh
@@ -14,12 +14,16 @@ fi
 
 . miracle-utils.sh
 
-WIFI_NAMES=$(find_wireless_network_interfaces)
-WIFI_COUNT=$(echo "$WIFI_NAMES" | wc -l)
+WIFI_COUNT=0
+WIFI_NAMES="$(find_wireless_network_interfaces)"
+if [ -n "$WIFI_NAMES" ]
+then
+  WIFI_COUNT=$(echo "$WIFI_NAMES" | wc -l)
+fi
 
 if [ 0 = $WIFI_COUNT ]
 then
-   echo There is no wireless devices avaliable
+   echo There is no wireless devices available
    exit 1
 elif [ 1 = $WIFI_COUNT ]
 then