diff --git a/unittests/ADT/CMakeLists.txt b/unittests/ADT/CMakeLists.txt
index cb9a9092b56..94f7fda2a9e 100644
--- a/unittests/ADT/CMakeLists.txt
+++ b/unittests/ADT/CMakeLists.txt
@@ -13,6 +13,7 @@ set(ADTSources
   FoldingSet.cpp
   HashingTest.cpp
   ilistTest.cpp
+  ImmutableMapTest.cpp
   ImmutableSetTest.cpp
   IntEqClassesTest.cpp
   IntervalMapTest.cpp