diff --git a/src/hb-shaper-private.hh b/src/hb-shaper-private.hh
index 9d30c1ea0..29c449394 100644
--- a/src/hb-shaper-private.hh
+++ b/src/hb-shaper-private.hh
@@ -95,7 +95,10 @@ hb_##shaper##_shaper_##object##_data_ensure (hb_##object##_t *object) \
     if (unlikely (!data)) \
       data = (HB_SHAPER_DATA_TYPE (shaper, object) *) HB_SHAPER_DATA_INVALID; \
     if (!hb_atomic_ptr_cmpexch (&HB_SHAPER_DATA (shaper, object), NULL, data)) { \
-      HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \
+      if (data && \
+	  data != HB_SHAPER_DATA_INVALID && \
+	  data != HB_SHAPER_DATA_SUCCEEDED) \
+	HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \
       goto retry; \
     } \
   } \