diff --git a/config/opal_config_threads.m4 b/config/opal_config_threads.m4
index 80c2042649..ca1f1efc07 100644
--- a/config/opal_config_threads.m4
+++ b/config/opal_config_threads.m4
@@ -101,7 +101,7 @@ if test "$THREAD_TYPE" = "posix"; then
 else
     AC_DEFINE(OPAL_HAVE_POSIX_THREADS, 0)
 
-    TRHEAD_CFLAGS=
+    THREAD_CFLAGS=
     THREAD_FCFLAGS=
     THREAD_CXXFLAGS=
     THREAD_CPPFLAGS=