diff --git a/src/H5FL.c b/src/H5FL.c
index 82cc41c3968..460b27b4399 100644
--- a/src/H5FL.c
+++ b/src/H5FL.c
@@ -272,12 +272,30 @@ H5FL_init(void)
 } /* end H5FL_init() */
 #endif /* H5_HAVE_CONCURRENCY */
 
+#ifdef H5_HAVE_THREADS
+#warning "H5_HAVE_THREADS"
+#else /* H5_HAVE_THREADS */
+#warning "NOT H5_HAVE_THREADS"
+#endif /* H5_HAVE_THREADS */
+
+#ifdef H5_HAVE_THREADSAFE_API
+#warning "H5_HAVE_THREADSAFE_API"
+#else /* H5_HAVE_THREADSAFE_API */
+#warning "NOT H5_HAVE_THREADSAFE_API"
+#endif /* H5_HAVE_THREADSAFE_API */
+
 #ifdef H5_HAVE_CONCURRENCY
-#error "H5_HAVE_CONCURRENCY"
+#warning "H5_HAVE_CONCURRENCY"
 #else /* H5_HAVE_CONCURRENCY */
-#error "NOT H5_HAVE_CONCURRENCY"
+#warning "NOT H5_HAVE_CONCURRENCY"
 #endif /* H5_HAVE_CONCURRENCY */
 
+#ifdef H5_HAVE_STDATOMIC_H
+#warning "H5_HAVE_STDATOMIC_H"
+#else /* H5_HAVE_STDATOMIC_H */
+#warning "NOT H5_HAVE_STDATOMIC_H"
+#endif /* H5_HAVE_STDATOMIC_H */
+
 /*--------------------------------------------------------------------------
  NAME
     H5FL_term_package