diff --git a/pmb/config/__init__.py b/pmb/config/__init__.py
index 937ae47b..e0b1fc1b 100644
--- a/pmb/config/__init__.py
+++ b/pmb/config/__init__.py
@@ -242,9 +242,10 @@ Flasher abstraction. Allowed variables:
 $BOOT: Path to the /boot partition
 $FLAVOR: Kernel flavor
 $IMAGE: Path to the system partition image
+$PARTITION_SYSTEM: Partition to flash the system image
 
 Fastboot specific: $KERNEL_CMDLINE
-Heimdall specific: $PARTITION_KERNEL, $PARTITION_INITFS, $PARTITION_SYSTEM
+Heimdall specific: $PARTITION_KERNEL, $PARTITION_INITFS
 """
 flashers = {
     "fastboot": {
@@ -252,7 +253,7 @@ flashers = {
         "actions":
                 {
                     "list_devices": [["fastboot", "devices", "-l"]],
-                    "flash_system": [["fastboot", "flash", "system", "$IMAGE"]],
+                    "flash_system": [["fastboot", "flash", "$PARTITION_SYSTEM", "$IMAGE"]],
                     "flash_kernel": [["fastboot", "flash", "boot", "$BOOT/boot.img-$FLAVOR"]],
                     "boot": [["fastboot", "-c", "$KERNEL_CMDLINE", "boot", "$BOOT/boot.img-$FLAVOR"]],
 
diff --git a/pmb/flasher/run.py b/pmb/flasher/run.py
index 34934c59..feaf228e 100644
--- a/pmb/flasher/run.py
+++ b/pmb/flasher/run.py
@@ -34,6 +34,13 @@ def run(args, action, flavor=None):
     if "cmdline" in args and args.cmdline:
         _cmdline = args.cmdline
 
+    if method == "fastboot":
+        _partition_system = "system"
+    else:
+        _partition_system = args.deviceinfo["flash_heimdall_partition_system"] or "SYSTEM"
+    if "partition" in args and args.partition:
+        _partition_system = args.partition
+
     # Variable setup
     vars = {
         "$BOOT": "/mnt/rootfs_" + args.device + "/boot",
@@ -42,7 +49,7 @@ def run(args, action, flavor=None):
         "$KERNEL_CMDLINE": _cmdline,
         "$PARTITION_KERNEL": args.deviceinfo["flash_heimdall_partition_kernel"] or "KERNEL",
         "$PARTITION_INITFS": args.deviceinfo["flash_heimdall_partition_initfs"] or "RECOVERY",
-        "$PARTITION_SYSTEM": args.deviceinfo["flash_heimdall_partition_system"] or "SYSTEM",
+        "$PARTITION_SYSTEM": _partition_system,
         "$RECOVERY_ZIP": "/mnt/buildroot_" + args.deviceinfo["arch"] +
                          "/var/lib/postmarketos-android-recovery-installer"
                          "/pmos-" + args.device + ".zip",
diff --git a/pmb/parse/arguments.py b/pmb/parse/arguments.py
index eb4914f0..c2cdc303 100644
--- a/pmb/parse/arguments.py
+++ b/pmb/parse/arguments.py
@@ -50,8 +50,12 @@ def arguments_flasher(subparser):
     for action in [boot, flash_kernel]:
         action.add_argument("--flavor", default=None)
 
+    # Flash system
+    flash_system = sub.add_parser("flash_system", help="flash the system partition")
+    flash_system.add_argument("--partition", default=None, help="partition to flash"
+                              " the system image")
+
     # Actions without extra arguments
-    sub.add_parser("flash_system", help="flash the system partition")
     sub.add_parser("sideload", help="sideload recovery zip")
     sub.add_parser("list_flavors", help="list installed kernel flavors" +
                    " inside the device rootfs chroot on this computer")