diff --git a/copyparty/th_srv.py b/copyparty/th_srv.py
index 8520d3d0..c28d2e83 100644
--- a/copyparty/th_srv.py
+++ b/copyparty/th_srv.py
@@ -8,7 +8,7 @@ import threading
 import subprocess as sp
 
 from .__init__ import PY2
-from .util import fsenc, Queue, Cooldown, BytesIO
+from .util import fsenc, mchkcmd, Queue, Cooldown, BytesIO
 from .mtag import HAVE_FFMPEG, HAVE_FFPROBE, ffprobe
 
 
@@ -299,8 +299,7 @@ class ThumbSrv(object):
 
         cmd += [fsenc(tpath)]
 
-        p = sp.Popen(cmd, stdout=sp.PIPE, stderr=sp.PIPE)
-        p.communicate()
+        mchkcmd(*cmd)
 
     def poke(self, tdir):
         if not self.poke_cd.poke(tdir):
diff --git a/copyparty/util.py b/copyparty/util.py
index 37971732..697aa5b6 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -985,6 +985,17 @@ def chkcmd(*argv):
     return sout, serr
 
 
+def mchkcmd(*argv, timeout=10):
+    if PY2:
+        with open(os.devnull, "wb") as f:
+            rv = sp.call(argv, stdout=f, stderr=f)
+    else:
+        rv = sp.call(argv, stdout=sp.DEVNULL, stderr=sp.DEVNULL, timeout=timeout)
+
+    if rv:
+        raise sp.CalledProcessError(rv, (argv[0], b"...", argv[-1]))
+
+
 def gzip_orig_sz(fn):
     with open(fsenc(fn), "rb") as f:
         f.seek(-4, 2)