diff --git a/copyparty/__main__.py b/copyparty/__main__.py
index ce41be5a..d7b6bf51 100644
--- a/copyparty/__main__.py
+++ b/copyparty/__main__.py
@@ -1651,7 +1651,7 @@ def add_safety(ap):
     th_bwrap = ""
     if HAVE_BWRAP:
         zsl = [
-            "bwrap",
+            HAVE_BWRAP,
             "--proc /proc",
             "--tmpfs /tmp",
             "--tmpfs /var",
@@ -1711,6 +1711,9 @@ def add_safety(ap):
     ap2.add_argument("--acam", metavar="V[,V]", type=u, default="GET,HEAD", help="Access-Control-Allow-Methods; list of methods to accept from offsite ('*' behaves like \033[33m--acao\033[0m's description)")
     if not ANYWIN and not UNIX:
         ap2.add_argument("--th-bwrap", metavar="CMD", type=u, default=th_bwrap, help="optional bwrap sandbox command for FFmpeg and dcraw (Linux-only)")
+        ap2.add_argument("--use-bwrap", metavar="C", type=u, default="a", help="a/n/f; [\033[32ma\033[0m]=auto (yes if the program 'bwrap' exists (assumes it works)), [\033[32mn\033[0m]=no (assumes bwrap is broken), [\033[32mf\033[0m]=force (disables FFmpeg if bwrap unavailable)")
+    else:
+        ap2.add_argument("--use-bwrap", metavar="C", type=u, default="n", help=argparse.SUPPRESS)
 
 
 def add_salt(ap, fk_salt, dk_salt, ah_salt):
diff --git a/copyparty/svchub.py b/copyparty/svchub.py
index fee403e7..4b653ce8 100644
--- a/copyparty/svchub.py
+++ b/copyparty/svchub.py
@@ -1188,6 +1188,17 @@ class SvcHub(object):
         al.th_covers_set = set(al.th_covers)
         al.th_coversd_set = set(al.th_coversd)
 
+        zs = al.use_bwrap.strip().lower()
+        if zs == "a":
+            if not HAVE_BWRAP:
+                al.th_bwrap = ""
+        elif zs == "n":
+            al.th_bwrap = ""
+        elif zs == "f":
+            al.th_bwrap = al.th_bwrap or "bwrap-not-available"
+        else:
+            raise Exception("--use-bwrap must be a/n/f")
+
         for k in "c".split(" "):
             if self.args.env_expand in (0, 2):
                 break
diff --git a/scripts/docker/innvikler.sh b/scripts/docker/innvikler.sh
index 4495e740..54540bff 100644
--- a/scripts/docker/innvikler.sh
+++ b/scripts/docker/innvikler.sh
@@ -48,6 +48,7 @@ cat >initcfg <<'EOF'
 [global]
   chdir: /w
   no-crt
+  use-bwrap: n
 
 % /cfg
 EOF