diff --git a/CMakeLists.txt b/CMakeLists.txt
index 31662ba..f15b60f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -158,6 +158,7 @@
     src/set.c
     src/context.c
     src/tree_schema.c
+    src/tree_schema_helpers.c
     src/parser_yang.c
     src/xml.c)