diff --git a/README b/README
index 6c62ae8898..439b599ce0 100644
--- a/README
+++ b/README
@@ -136,6 +136,9 @@ General notes
     with Oracle Solaris Studio 12.5
   - OpenBSD.  Requires configure options --enable-mca-no-build=patcher
     and --disable-slopen with this release.
+  - Problems have been reported when building Open MPI on FreeBSD 11.1
+    using the clang-4.0 system compiler. A workaround is to build
+    Open MPI using the GNU compiler.
 
 Compiler Notes
 --------------