diff --git a/docs/changelog.rst b/docs/changelog.rst
index dc8453ab..34654d57 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -10,6 +10,12 @@ v0.19.0 (UNRELEASED)
 
 Feature release.
 
+**Backend API**
+
+- Imports of the backend API from :mod:`mopidy.backends` no longer works. The
+  new API introuced in v0.18 is now required. Most extensions already use the
+  new API location.
+
 **MPD frontend**
 
 - Proper command tokenization for MPD requests. This replaces the old regex
diff --git a/mopidy/backends/__init__.py b/mopidy/backends/__init__.py
deleted file mode 100644
index baffc488..00000000
--- a/mopidy/backends/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from __future__ import unicode_literals
diff --git a/mopidy/backends/base.py b/mopidy/backends/base.py
deleted file mode 100644
index aed6ce3e..00000000
--- a/mopidy/backends/base.py
+++ /dev/null
@@ -1,17 +0,0 @@
-from __future__ import unicode_literals
-
-from mopidy.backend import (
-    Backend,
-    LibraryProvider as BaseLibraryProvider,
-    PlaybackProvider as BasePlaybackProvider,
-    PlaylistsProvider as BasePlaylistsProvider)
-
-
-# Make classes previously residing here available in the old location for
-# backwards compatibility with extensions targeting Mopidy < 0.18.
-__all__ = [
-    'Backend',
-    'BaseLibraryProvider',
-    'BasePlaybackProvider',
-    'BasePlaylistsProvider',
-]
diff --git a/mopidy/backends/dummy.py b/mopidy/backends/dummy.py
deleted file mode 100644
index 7c13c9b1..00000000
--- a/mopidy/backends/dummy.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from __future__ import unicode_literals
-
-# Make classes previously residing here available in the old location for
-# backwards compatibility with extensions targeting Mopidy < 0.18.
-from mopidy.backend.dummy import *  # noqa
diff --git a/mopidy/backends/listener.py b/mopidy/backends/listener.py
deleted file mode 100644
index 0b551f26..00000000
--- a/mopidy/backends/listener.py
+++ /dev/null
@@ -1,8 +0,0 @@
-from __future__ import unicode_literals
-
-from mopidy.backend import BackendListener
-
-
-# Make classes previously residing here available in the old location for
-# backwards compatibility with extensions targeting Mopidy < 0.18.
-__all__ = ['BackendListener']