diff --git a/opal/runtime/opal.h b/opal/runtime/opal.h
index 5643fa1b01..2b35ea8eca 100644
--- a/opal/runtime/opal.h
+++ b/opal/runtime/opal.h
@@ -21,6 +21,8 @@
 #ifndef OPAL_H
 #define OPAL_H
 
+#include "opal_config.h"
+
 #if defined(c_plusplus) || defined(__cplusplus)
 extern "C" {
 #endif