diff --git a/memcheck/tests/Makefile.am b/memcheck/tests/Makefile.am
index 5de1960ca..610cee00d 100644
--- a/memcheck/tests/Makefile.am
+++ b/memcheck/tests/Makefile.am
@@ -318,7 +318,6 @@ check_PROGRAMS = \
 	partial_load pdb-realloc pdb-realloc2 \
 	pipe pointer-trace \
 	post-syscall \
-	reach_thread_register \
 	realloc1 realloc2 realloc3 \
 	recursive-merge \
 	sbfragment \
@@ -353,6 +352,10 @@ if HAVE_PTHREAD_SETNAME_NP
 check_PROGRAMS += threadname 
 endif
 
+if HAVE_PTHREAD_BARRIER
+check_PROGRAMS += reach_thread_register
+endif
+
 if HAVE_GSTABS
 check_PROGRAMS += deep_templates
 endif
diff --git a/memcheck/tests/reach_thread_register.c b/memcheck/tests/reach_thread_register.c
index 816c1239e..b70d7e188 100644
--- a/memcheck/tests/reach_thread_register.c
+++ b/memcheck/tests/reach_thread_register.c
@@ -1,3 +1,5 @@
+#define _GNU_SOURCE 
+
 #include <pthread.h>
 #include <sched.h>
 #include <stdio.h>