diff --git a/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp b/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp
--- a/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp
+++ b/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp
@@ -22,3 +22,7 @@
 // ADDITIONAL_COMPILE_FLAGS: -fexperimental-library
 
 #include <version>
+
+#ifdef _LIBCPP_HAS_NO_INCOMPLETE_PSTL
+#  error "-fexperimental-library should enable the PSTL"
+#endif