diff --git a/src/hb-ot-hdmx-table.hh b/src/hb-ot-hdmx-table.hh
index d25570585..6bf492cbf 100644
--- a/src/hb-ot-hdmx-table.hh
+++ b/src/hb-ot-hdmx-table.hh
@@ -34,67 +34,69 @@ namespace OT {
 #define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')
 
 
-struct DeviceRecord
-{
-  struct SubsetView
-  {
-    const DeviceRecord *source_device_record;
-    hb_subset_plan_t *subset_plan;
-
-    inline void init(const DeviceRecord *source_device_record,
-                     hb_subset_plan_t   *subset_plan)
-    {
-      this->source_device_record = source_device_record;
-      this->subset_plan = subset_plan;
-    }
-
-    inline unsigned int len () const
-    {
-      return this->subset_plan->gids_to_retain_sorted.len;
-    }
-
-    inline const HBUINT8& operator [] (unsigned int i) const
-    {
-      if (unlikely (i >= len())) return Null(HBUINT8);
-      hb_codepoint_t gid = this->subset_plan->gids_to_retain_sorted [i];
-      return this->source_device_record->widths[gid];
-    }
-  };
-
-  static inline unsigned int get_size (unsigned int count)
-  {
-    unsigned int raw_size = min_size + count * HBUINT8::static_size;
-    if (raw_size % 4)
-      /* Align to 32 bits */
-      return raw_size + (4 - (raw_size % 4));
-    return raw_size;
-  }
-
-  inline bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
-  {
-    TRACE_SERIALIZE (this);
-
-    if (unlikely (!c->allocate_size<DeviceRecord> (get_size (subset_view.len()))))
-      return_trace (false);
-
-    this->pixel_size.set (subset_view.source_device_record->pixel_size);
-    this->max_width.set (subset_view.source_device_record->max_width);
-
-    for (unsigned int i = 0; i < subset_view.len(); i++)
-      widths[i].set (subset_view[i]);
-
-    return_trace (true);
-  }
-
-  HBUINT8 pixel_size;
-  HBUINT8 max_width;
-  HBUINT8 widths[VAR];
-
-  DEFINE_SIZE_MIN (2);
-};
 
 struct hdmx
 {
+  static const hb_tag_t tableTag = HB_OT_TAG_glyf;
+
+  struct DeviceRecord
+  {
+    struct SubsetView
+    {
+      const DeviceRecord *source_device_record;
+      hb_subset_plan_t *subset_plan;
+
+      inline void init(const DeviceRecord *source_device_record,
+                       hb_subset_plan_t   *subset_plan)
+      {
+        this->source_device_record = source_device_record;
+        this->subset_plan = subset_plan;
+      }
+
+      inline unsigned int len () const
+      {
+        return this->subset_plan->gids_to_retain_sorted.len;
+      }
+
+      inline const HBUINT8& operator [] (unsigned int i) const
+      {
+        if (unlikely (i >= len())) return Null(HBUINT8);
+        hb_codepoint_t gid = this->subset_plan->gids_to_retain_sorted [i];
+        return this->source_device_record->widths[gid];
+      }
+    };
+
+    static inline unsigned int get_size (unsigned int count)
+    {
+      unsigned int raw_size = min_size + count * HBUINT8::static_size;
+      if (raw_size % 4)
+        /* Align to 32 bits */
+        return raw_size + (4 - (raw_size % 4));
+      return raw_size;
+    }
+
+    inline bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
+    {
+      TRACE_SERIALIZE (this);
+
+      if (unlikely (!c->allocate_size<DeviceRecord> (get_size (subset_view.len()))))
+        return_trace (false);
+
+      this->pixel_size.set (subset_view.source_device_record->pixel_size);
+      this->max_width.set (subset_view.source_device_record->max_width);
+
+      for (unsigned int i = 0; i < subset_view.len(); i++)
+        widths[i].set (subset_view[i]);
+
+      return_trace (true);
+    }
+
+    HBUINT8 pixel_size;
+    HBUINT8 max_width;
+    HBUINT8 widths[VAR];
+
+    DEFINE_SIZE_MIN (2);
+  };
 
   inline unsigned int get_size (void) const
   {