diff --git a/src/hb-mutex-private.hh b/src/hb-mutex-private.hh
index a81d3624d5c91284df4caf6e957a7e474a70bde5..f87473d319578404218e0274be523358f1c911ea 100644
--- a/src/hb-mutex-private.hh
+++ b/src/hb-mutex-private.hh
@@ -100,6 +100,14 @@ typedef volatile int hb_mutex_t;
 #endif
 
 
+struct hb_static_mutex_t : hb_mutex_t
+{
+  hb_static_mutex_t (void) {
+    hb_mutex_init (*this);
+  }
+};
+
+
 HB_END_DECLS
 
 #endif /* HB_MUTEX_PRIVATE_HH */