diff --git a/sigal/image.py b/sigal/image.py
index 58d2752..31494bb 100644
--- a/sigal/image.py
+++ b/sigal/image.py
@@ -159,7 +159,10 @@ def process_image(filepath, outpath, settings):
                                fit=settings['thumb_fit'], options=options)
     except Exception as e:
         logger.info('Failed to process: %r', e)
-        return Status.FAILURE
+        if logger.getEffectiveLevel() == logging.DEBUG:
+            raise
+        else:
+            return Status.FAILURE
 
     return Status.SUCCESS
 
diff --git a/sigal/video.py b/sigal/video.py
index 41cc360..d120aa9 100644
--- a/sigal/video.py
+++ b/sigal/video.py
@@ -133,11 +133,7 @@ def generate_thumbnail(source, outname, box, delay, fit=True, options=None):
     cmd = ['ffmpeg', '-i', source, '-an', '-r', '1',
            '-ss', delay, '-vframes', '1', '-y', tmpfile]
     logger.debug('Create thumbnail for video: %s', ' '.join(cmd))
-
-    try:
-        check_subprocess(cmd, source, outname)
-    except Exception:
-        return
+    check_subprocess(cmd, source, outname)
 
     # use the generate_thumbnail function from sigal.image
     image.generate_thumbnail(tmpfile, outname, box, fit, options)
@@ -169,7 +165,10 @@ def process_video(filepath, outpath, settings):
             generate_video(filepath, outname, settings,
                            options=settings.get(video_format + '_options'))
     except Exception:
-        return Status.FAILURE
+        if logger.getEffectiveLevel() == logging.DEBUG:
+            raise
+        else:
+            return Status.FAILURE
 
     if settings['make_thumbs']:
         thumb_name = os.path.join(outpath, get_thumb(settings, filename))
@@ -179,6 +178,9 @@ def process_video(filepath, outpath, settings):
                 settings['thumb_video_delay'], fit=settings['thumb_fit'],
                 options=settings['jpg_options'])
         except Exception:
-            return Status.FAILURE
+            if logger.getEffectiveLevel() == logging.DEBUG:
+                raise
+            else:
+                return Status.FAILURE
 
     return Status.SUCCESS
diff --git a/tests/test_gallery.py b/tests/test_gallery.py
index 066a739..865eceb 100644
--- a/tests/test_gallery.py
+++ b/tests/test_gallery.py
@@ -1,12 +1,14 @@
 # -*- coding:utf-8 -*-
 
 import locale
+import logging
 import os
 import pytest
 import datetime
 
 from os.path import join
 from sigal.gallery import Album, Media, Image, Video, Gallery
+from sigal.video import SubprocessException
 
 CURRENT_DIR = os.path.dirname(__file__)
 
@@ -218,6 +220,8 @@ def test_gallery(settings, tmpdir):
     "Test the Gallery class."
 
     settings['destination'] = str(tmpdir)
+    settings['webm_options'] = ['-missing-option', 'foobar']
+
     gal = Gallery(settings, ncpu=1)
     gal.build()
 
@@ -229,6 +233,11 @@ def test_gallery(settings, tmpdir):
 
     assert '<title>Sigal test gallery</title>' in html
 
+    logging.getLogger('sigal').setLevel(logging.DEBUG)
+    gal = Gallery(settings, ncpu=1)
+    with pytest.raises(SubprocessException):
+        gal.build()
+
 
 def test_empty_dirs(settings):
     gal = Gallery(settings, ncpu=1)