diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7cf9b2034..7dba2b67f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -479,7 +479,7 @@ set(EXECUTABLE_OUTPUT_PATH ${dir} CACHE PATH "Build directory" FORCE)
 set(LIBRARY_OUTPUT_PATH ${dir} CACHE PATH "Build directory" FORCE)
 
 # Add each component.
-add_subdirectory("external")
+add_subdirectory("external" EXCLUDE_FROM_ALL)
 add_subdirectory("es-core")
 add_subdirectory("es-app")