diff --git a/libatomic/config/arm/host-config.h b/libatomic/config/arm/host-config.h
index bbf4a3f84c3f3ae21fb2162aab68bdedf3fbdcb4..ef16fad2a35ec9055e918849e69a1a0e23b62838 100644
--- a/libatomic/config/arm/host-config.h
+++ b/libatomic/config/arm/host-config.h
@@ -1,4 +1,23 @@
 /* Avoiding the DMB (or kernel helper) can be a good thing.  */
 #define WANT_SPECIALCASE_RELAXED
 
+/* Glibc, at least, uses acq_rel in its pthread mutex
+   implementation.  If the user is asking for seq_cst,
+   this is insufficient.  */
+
+static inline void __attribute__((always_inline, artificial))
+pre_seq_barrier(int model)
+{
+  if (model == __ATOMIC_SEQ_CST)
+    __atomic_thread_fence (__ATOMIC_SEQ_CST);
+}
+
+static inline void __attribute__((always_inline, artificial))
+post_seq_barrier(int model)
+{
+  pre_seq_barrier(model);
+}
+
+#define pre_post_seq_barrier 1
+
 #include_next <host-config.h>