diff --git a/CMakeLists.txt b/CMakeLists.txt
index 790ab5f093bd523fc120a375031bb2ad3a0a662c..ec7201d3139408ba7fbf2e180bc87808a86a799d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -382,8 +382,10 @@ endif()
 add_subdirectory (external)
 
 ### Base directories
-add_subdirectory (algo)
 add_subdirectory (core)
+if (${CMAKE_CXX_STANDARD} EQUAL 17)
+  add_subdirectory (algo)
+endif()
 add_subdirectory (sim)
 add_subdirectory (reco)
 add_subdirectory (analysis)