diff --git a/swh/web/common/service.py b/swh/web/common/service.py
--- a/swh/web/common/service.py
+++ b/swh/web/common/service.py
@@ -88,7 +88,9 @@
 
     """
     algo, hash = query.parse_hash(q)
-    found = storage.content_find({algo: hash})
+    found = None
+    if storage.content_find({algo: hash}):
+        found = storage.content_find({algo: hash})[0]
     return {'found': converters.from_content(found),
             'algo': algo}
 
@@ -104,7 +106,7 @@
     """
     algo, hash = query.parse_hash(q)
     found = storage.content_find({algo: hash})
-    return {'found': found is not None}
+    return {'found': bool(found)}
 
 
 def _lookup_content_sha1(q):
@@ -122,7 +124,7 @@
         hashes = storage.content_find({algo: hash})
         if not hashes:
             return None
-        return hashes['sha1']
+        return hashes[0]['sha1']
     return hash
 
 
@@ -717,7 +719,9 @@
                 'content': list(map(converters.from_directory_entry,
                                     directory_entries))}
     elif entity['type'] == 'file':  # content
-        content = storage.content_find({'sha1_git': entity['target']})
+        content = None
+        if storage.content_find({'sha1_git': entity['target']}):
+            content = storage.content_find({'sha1_git': entity['target']})[0]
         if with_data:
             c = _first_element(storage.content_get([content['sha1']]))
             content['data'] = c['data']
@@ -751,7 +755,7 @@
     if not c:
         raise NotFoundExc('Content with %s checksum equals to %s not found!' %
                           (algo, hashutil.hash_to_hex(hash)))
-    return converters.from_content(c)
+    return converters.from_content(c[0])
 
 
 def lookup_content_raw(q):