diff --git a/modules.d/40network/ifname-genrules.sh b/modules.d/40network/ifname-genrules.sh
index e188c88b..b0b429cc 100755
--- a/modules.d/40network/ifname-genrules.sh
+++ b/modules.d/40network/ifname-genrules.sh
@@ -7,6 +7,8 @@ if ! getarg ifname= >/dev/null ; then
     return
 fi
 
+command -v parse_ifname_opts >/dev/null || . /lib/net-lib.sh
+
 {
     for p in $(getargs ifname=); do
         parse_ifname_opts $p
diff --git a/modules.d/40network/net-lib.sh b/modules.d/40network/net-lib.sh
index 9132e4d2..9a1e0040 100644
--- a/modules.d/40network/net-lib.sh
+++ b/modules.d/40network/net-lib.sh
@@ -289,3 +289,19 @@ ip_to_var() {
         esac
     fi
 }
+
+parse_ifname_opts() {
+    local IFS=:
+    set $1
+
+    case $# in
+        7)
+            ifname_if=$1
+            # udev requires MAC addresses to be lower case
+            ifname_mac=$(echo $2:$3:$4:$5:$6:$7 | sed 'y/ABCDEF/abcdef/')
+            ;;
+        *)
+            die "Invalid arguments for ifname="
+            ;;
+    esac
+}
diff --git a/modules.d/40network/parse-ifname.sh b/modules.d/40network/parse-ifname.sh
index ce73a72a..d5156b37 100755
--- a/modules.d/40network/parse-ifname.sh
+++ b/modules.d/40network/parse-ifname.sh
@@ -18,21 +18,7 @@ if ! getarg ifname= >/dev/null ; then
     return
 fi
 
-parse_ifname_opts() {
-    local IFS=:
-    set $1
-
-    case $# in
-        7)
-            ifname_if=$1
-            # udev requires MAC addresses to be lower case
-            ifname_mac=$(echo $2:$3:$4:$5:$6:$7 | sed 'y/ABCDEF/abcdef/')
-            ;;
-        *)
-            die "Invalid arguments for ifname="
-            ;;
-    esac
-}
+command -v parse_ifname_opts >/dev/null || . /lib/net-lib.sh
 
 # Check ifname= lines
 for p in $(getargs ifname=); do