diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml
index fe044d236a..bc1ff7876d 100644
--- a/man/systemd.net-naming-scheme.xml
+++ b/man/systemd.net-naming-scheme.xml
@@ -376,7 +376,12 @@
           of the <filename>function_id</filename> device attribute. This attribute is now used to build the
           <varname>ID_NET_NAME_SLOT</varname>. Before that, all slot names were parsed as decimal
           numbers, which could either result in an incorrect value of the <varname>ID_NET_NAME_SLOT</varname>
-          property or none at all.</para></listitem>
+          property or none at all.</para>
+
+          <para>Some firmware and hypervisor implementations report unreasonable high numbers for the onboard
+          index. To prevent the generation of bogus onbard interface names, index numbers greater than 16381
+          (2^14-1) were ignored. For s390 PCI devices index values up to 65535 (2^16-1) are valid. To account
+          for that, the limit is increased to now 65535.</para></listitem>
         </varlistentry>
 
       </variablelist>
diff --git a/src/shared/netif-naming-scheme.h b/src/shared/netif-naming-scheme.h
index f719744d56..c0f94d0407 100644
--- a/src/shared/netif-naming-scheme.h
+++ b/src/shared/netif-naming-scheme.h
@@ -33,6 +33,7 @@ typedef enum NamingSchemeFlags {
         NAMING_NSPAWN_LONG_HASH    = 1 << 8, /* Shorten nspawn interfaces by including 24bit hash, instead of simple truncation  */
         NAMING_BRIDGE_NO_SLOT      = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */
         NAMING_SLOT_FUNCTION_ID    = 1 << 10, /* Use function_id if present to identify PCI hotplug slots */
+        NAMING_16BIT_INDEX         = 1 << 11, /* Allow full 16-bit for the onboard index */
 
         /* And now the masks that combine the features above */
         NAMING_V238 = 0,
@@ -42,7 +43,7 @@ typedef enum NamingSchemeFlags {
         NAMING_V243 = NAMING_V241 | NAMING_NETDEVSIM | NAMING_LABEL_NOPREFIX,
         NAMING_V245 = NAMING_V243 | NAMING_NSPAWN_LONG_HASH,
         NAMING_V247 = NAMING_V245 | NAMING_BRIDGE_NO_SLOT,
-        NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID,
+        NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID | NAMING_16BIT_INDEX,
 
         _NAMING_SCHEME_FLAGS_INVALID = -EINVAL,
 } NamingSchemeFlags;
diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index 088bfe38d9..33601151a6 100644
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -37,7 +37,8 @@
 #include "strxcpyx.h"
 #include "udev-builtin.h"
 
-#define ONBOARD_INDEX_MAX (16*1024-1)
+#define ONBOARD_14BIT_INDEX_MAX ((1U << 14) - 1)
+#define ONBOARD_16BIT_INDEX_MAX ((1U << 16) - 1)
 
 enum netname_type{
         NET_UNDEF,
@@ -162,6 +163,16 @@ static int get_virtfn_info(sd_device *dev, struct netnames *names, struct virtfn
         return 0;
 }
 
+static bool is_valid_onboard_index(unsigned long idx) {
+        /* Some BIOSes report rubbish indexes that are excessively high (2^24-1 is an index VMware likes to
+         * report for example). Let's define a cut-off where we don't consider the index reliable anymore. We
+         * pick some arbitrary cut-off, which is somewhere beyond the realistic number of physical network
+         * interface a system might have. Ideally the kernel would already filter this crap for us, but it
+         * doesn't currently. The initial cut-off value (2^14-1) was too conservative for s390 PCI which
+         * allows for index values up 2^16-1 which is now enabled with the NAMING_16BIT_INDEX naming flag. */
+        return idx <= (naming_scheme_has(NAMING_16BIT_INDEX) ? ONBOARD_16BIT_INDEX_MAX : ONBOARD_14BIT_INDEX_MAX);
+}
+
 /* retrieve on-board index number and label from firmware */
 static int dev_pci_onboard(sd_device *dev, struct netnames *names) {
         unsigned long idx, dev_port = 0;
@@ -184,12 +195,7 @@ static int dev_pci_onboard(sd_device *dev, struct netnames *names) {
         if (idx == 0 && !naming_scheme_has(NAMING_ZERO_ACPI_INDEX))
                 return -EINVAL;
 
-        /* Some BIOSes report rubbish indexes that are excessively high (2^24-1 is an index VMware likes to
-         * report for example). Let's define a cut-off where we don't consider the index reliable anymore. We
-         * pick some arbitrary cut-off, which is somewhere beyond the realistic number of physical network
-         * interface a system might have. Ideally the kernel would already filter this crap for us, but it
-         * doesn't currently. */
-        if (idx > ONBOARD_INDEX_MAX)
+        if (!is_valid_onboard_index(idx))
                 return -ENOENT;
 
         /* kernel provided port index for multiple ports on a single PCI function */