diff --git a/src/calibre/db/cache.py b/src/calibre/db/cache.py
index 611efc80f8..be3a5ab5fb 100644
--- a/src/calibre/db/cache.py
+++ b/src/calibre/db/cache.py
@@ -1480,7 +1480,7 @@ class Cache(object):
         if title:
             if isbytestring(title):
                 title = title.decode(preferred_encoding, 'replace')
-            q = icu_lower(title)
+            q = icu_lower(title).strip()
             for title in self.fields['title'].table.book_col_map.itervalues():
                 if q == icu_lower(title):
                     return True
diff --git a/src/calibre/ebooks/metadata/worker.py b/src/calibre/ebooks/metadata/worker.py
index cb9c1de179..795e6b0304 100644
--- a/src/calibre/ebooks/metadata/worker.py
+++ b/src/calibre/ebooks/metadata/worker.py
@@ -60,11 +60,13 @@ def run_import_plugins(paths, group_id, tdir):
         final_paths.append(path)
     return final_paths
 
+def has_book(mi, data_for_has_book):
+    return mi.title and icu_lower(mi.title.strip()) in data_for_has_book
+
 def read_metadata(paths, group_id, tdir, common_data=None):
     paths = run_import_plugins(paths, group_id, tdir)
     mi, opf, has_cover = serialize_metadata_for(paths, tdir, group_id)
     duplicate_info = None
-    if common_data is not None:
-        if isinstance(common_data, (set, frozenset)):
-            duplicate_info = mi.title and icu_lower(mi.title) in common_data
+    if isinstance(common_data, (set, frozenset)):
+        duplicate_info = has_book(mi, common_data)
     return paths, opf, has_cover, duplicate_info