diff --git a/lib_fiber/c/CMakeLists.txt b/lib_fiber/c/CMakeLists.txt
index daa1d58dd..0ebc21a3e 100644
--- a/lib_fiber/c/CMakeLists.txt
+++ b/lib_fiber/c/CMakeLists.txt
@@ -118,6 +118,7 @@ set(sources
 	${src}/fiber
 	${src}/common
 	${src}/event
+	${src}/sync
 	${src}/hook
 	${src}/dns
 )