diff --git a/pmb/install/_install.py b/pmb/install/_install.py
index ceb0c292..38f64a46 100644
--- a/pmb/install/_install.py
+++ b/pmb/install/_install.py
@@ -416,7 +416,11 @@ def install_system_image(args):
     pmb.chroot.shutdown(args, True)
 
     # Convert rootfs to sparse using img2simg
-    if args.deviceinfo["flash_sparse"] == "true" and not args.split and not args.sdcard:
+    sparse = args.sparse
+    if sparse is None:
+        sparse = args.deviceinfo["flash_sparse"] == "true"
+
+    if sparse and not args.split and not args.sdcard:
         logging.info("(native) make sparse rootfs")
         pmb.chroot.apk.install(args, ["android-tools"])
         sys_image = args.device + ".img"
diff --git a/pmb/parse/arguments.py b/pmb/parse/arguments.py
index 87b690cb..72d261af 100644
--- a/pmb/parse/arguments.py
+++ b/pmb/parse/arguments.py
@@ -488,6 +488,13 @@ def arguments():
     install.add_argument("--no-base",
                          help="do not install postmarketos-base (advanced)",
                          action="store_false", dest="install_base")
+    group = install.add_mutually_exclusive_group()
+    group.add_argument("--sparse", help="generate sparse image file"
+                       " (even if unsupported by device)", default=None,
+                       action="store_true")
+    group.add_argument("--no-sparse", help="do not generate sparse image file"
+                       " (even if supported by device)", dest="sparse",
+                       action="store_false")
 
     # Action: checksum / aportgen / build
     checksum = sub.add_parser("checksum", help="update aport checksums")