diff --git a/etiquette/jsonify.py b/etiquette/jsonify.py
index 395e940..95c030b 100644
--- a/etiquette/jsonify.py
+++ b/etiquette/jsonify.py
@@ -33,7 +33,7 @@ def photo(p, include_albums=True, include_tags=True):
         'ratio': p.ratio,
         'area': p.area,
         'bytes': p.bytes,
-        'duration_str': p.duration_string(),
+        'duration_str': p.duration_string,
         'duration': p.duration,
         'bytes_str': p.bytestring(),
         'has_thumbnail': bool(p.thumbnail),
diff --git a/etiquette/objects.py b/etiquette/objects.py
index 6b679dd..dcca034 100644
--- a/etiquette/objects.py
+++ b/etiquette/objects.py
@@ -505,6 +505,7 @@ class Photo(ObjectBase):
             self.photodb.log.debug('Committing - delete photo')
             self.photodb.commit()
 
+    @property
     def duration_string(self):
         if self.duration is None:
             return None
diff --git a/templates/photo.html b/templates/photo.html
index 23e30c2..b30fb5e 100644
--- a/templates/photo.html
+++ b/templates/photo.html
@@ -169,7 +169,7 @@
         {% endif %}
         <li>Size: {{photo.bytestring()}}</li>
         {% if photo.duration %}
-            <li>Duration: {{photo.duration_string()}}</li>
+            <li>Duration: {{photo.duration_string}}</li>
         {% endif %}
             <li><a href="/file/{{photo.id}}{{photo.dot_extension}}?download=1">Download as {{photo.id}}.{{photo.extension}}</a></li>
             <li><a href="/file/{{photo.id}}{{photo.dot_extension}}?download=1&original_filename=1">Download as "{{photo.basename}}"</a></li>
diff --git a/templates/photo_card.html b/templates/photo_card.html
index ed8c68d..8b12a63 100644
--- a/templates/photo_card.html
+++ b/templates/photo_card.html
@@ -60,7 +60,7 @@
                 {{photo.width}}&times;{{photo.height}},
             {% endif %}
             {% if photo.duration %}
-                {{photo.duration_string()}},
+                {{photo.duration_string}},
             {% endif %}
             <a target="_blank" href="/file/{{photo.id}}.{{photo.extension}}">{{photo.bytestring()}}</a>
             </span>