diff --git a/wireguard-inject.sh b/wireguard-inject.sh
index 5069d05..3121dfd 100755
--- a/wireguard-inject.sh
+++ b/wireguard-inject.sh
@@ -57,7 +57,6 @@ declare -A interfaces
 declare -A previous_modtimes
 declare -A add_interfaces
 declare -A remove_interfaces
-modcount=0
 
 if [ -f "$MODFILE" ]
 then
@@ -87,8 +86,6 @@ do
     # if an interface has been modified, remove it then re-add it
     remove_interfaces[$iface]=1
     add_interfaces[$iface]=1
-
-    modcount=$(( modcount + 1 ))
 done
 
 ###########################################################################
@@ -147,7 +144,8 @@ done
 # all done
 
 # save the modified times if required
-if [ "$modcount" -gt 0 ]
+if [ "${#add_interfaces[@]}" -gt 0 ] ||
+       [ "${#remove_interfaces[@]}" -gt 0 ]
 then
     exec 3> "$MODFILE"
     for file in "${!modtimes[@]}"