--- CMakeLists.txt.orig	2017-11-12 20:15:25 UTC
+++ CMakeLists.txt
@@ -155,7 +155,7 @@ add_subdirectory(include)
 # recursively add source directories
 add_subdirectory(src)
 
-#if (NOT ENABLE_PSI4)
+if (ENABLE_TESTS)
     # test suite
     enable_testing()
     include(CTest)
@@ -163,7 +163,7 @@ add_subdirectory(src)
 
     # sample suite
     add_subdirectory(samples)
-#endif()
+endif()
 
 # Add all targets to the build-tree export set