diff --git a/src/wic/plugins/source/bootimg_efi.py b/src/wic/plugins/source/bootimg_efi.py
index 69aa38b..7d2175d 100644
--- a/src/wic/plugins/source/bootimg_efi.py
+++ b/src/wic/plugins/source/bootimg_efi.py
@@ -97,7 +97,7 @@ class BootimgEFIPlugin(SourcePlugin):
                         (get_bitbake_var("KERNEL_IMAGETYPE"), get_bitbake_var("INITRAMFS_LINK_NAME"))

             label = source_params.get('label')
-            label_conf = "root=%s" % creator.rootdev
+            label_conf = f"root={creator.rootdev}" if creator.rootdev else ""
             if label:
                 label_conf = "LABEL=%s" % label

@@ -186,7 +186,8 @@ class BootimgEFIPlugin(SourcePlugin):
             boot_conf += "linux /%s\n" % kernel

             label = source_params.get('label')
-            label_conf = "LABEL=Boot root=%s" % creator.rootdev
+            label_conf = "LABEL=Boot"
+            label_conf += f" root={creator.rootdev}" if creator.rootdev else ""
             if label:
                 label_conf = "LABEL=%s" % label

diff --git a/src/wic/plugins/source/bootimg_pcbios.py b/src/wic/plugins/source/bootimg_pcbios.py
index 1e5ec3a..b49d48d 100644
--- a/src/wic/plugins/source/bootimg_pcbios.py
+++ b/src/wic/plugins/source/bootimg_pcbios.py
@@ -231,8 +231,10 @@ class BootimgPcbiosPlugin(SourcePlugin):
             kernel = "/" + get_bitbake_var("KERNEL_IMAGETYPE")
             syslinux_conf += "KERNEL " + kernel + "\n"

-            syslinux_conf += "APPEND label=boot root=%s %s\n" % \
-                             (creator.rootdev, bootloader.append)
+            # Check if rootdev exists
+            root_param = f"root={creator.rootdev}" if creator.rootdev else ""
+
+            syslinux_conf += f"APPEND label=boot {root_param} {bootloader.append}\n"

         logger.debug("Writing syslinux config %s/syslinux.cfg", hdddir)
         cfg = open("%s/hdd/boot/syslinux.cfg" % cr_workdir, "w")