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
@@ -26,3 +26,7 @@
 #ifdef _LIBCPP_HAS_NO_INCOMPLETE_FORMAT
 #   error "-fexperimental-library should enable <format>"
 #endif
+
+#ifndef _LIBCPP_HAS_NO_INCOMPLETE_PSTL
+#  error "-fexperimental-library should enable the PSTL"
+#endif