diff --git a/include/boost/config/compiler/clang.hpp b/include/boost/config/compiler/clang.hpp
index 976a92c0..1067a800 100644
--- a/include/boost/config/compiler/clang.hpp
+++ b/include/boost/config/compiler/clang.hpp
@@ -12,10 +12,14 @@
 #  define BOOST_NO_EXCEPTIONS
 #endif
 
-#if !__has_feature(cxx_rtti)
+#if !__has_feature(cxx_rtti) && !defined(BOOST_NO_RTTI)
 #  define BOOST_NO_RTTI
 #endif
 
+#if !__has_feature(cxx_rtti) && !defined(BOOST_NO_TYPEID)
+#  define BOOST_NO_TYPEID
+#endif
+
 #if defined(__int64)
 #  define BOOST_HAS_MS_INT64
 #endif
diff --git a/include/boost/config/compiler/pgi.hpp b/include/boost/config/compiler/pgi.hpp
index 72199ac6..e818e6cb 100644
--- a/include/boost/config/compiler/pgi.hpp
+++ b/include/boost/config/compiler/pgi.hpp
@@ -21,7 +21,7 @@
 // options requested by configure --enable-test
 #define BOOST_HAS_PTHREADS
 #define BOOST_HAS_THREADS
-#undef BOOST_HAS_PTHREAD_YIELD
+#define BOOST_HAS_PTHREAD_YIELD
 #define BOOST_HAS_NRVO
 #define BOOST_HAS_LONG_LONG