diff --git a/src/sphinx/DetailedTopics/custom.rst b/src/sphinx/DetailedTopics/custom.rst
index 883ea7cdb..18440a5a6 100644
--- a/src/sphinx/DetailedTopics/custom.rst
+++ b/src/sphinx/DetailedTopics/custom.rst
@@ -26,6 +26,8 @@ contains the assembled jar. This is what the final ``build.sbt`` should contain:
 
 .. code-block:: scala
 
+    import AssemblyKeys._
+
     // the assembly settings
     assemblySettings