diff --git a/src/calibre/ebooks/chardet.py b/src/calibre/ebooks/chardet.py
index 52f4824528..7d016c8bda 100644
--- a/src/calibre/ebooks/chardet.py
+++ b/src/calibre/ebooks/chardet.py
@@ -109,14 +109,7 @@ _CHARSET_ALIASES = {"macintosh" : "mac-roman", "x-sjis" : "shift-jis"}
 def detect(bytestring):
     if isinstance(bytestring, str):
         bytestring = bytestring.encode('utf-8', 'replace')
-    try:
-        from calibre_extensions.uchardet import detect as implementation
-    except ImportError:
-        # People running from source without updated binaries
-        from cchardet import detect as cdi
-
-        def implementation(x):
-            return cdi(x).get('encoding') or ''
+    from calibre_extensions.uchardet import detect as implementation
     enc = implementation(bytestring).lower()
     return {'encoding': enc, 'confidence': 1 if enc else 0}