diff --git a/src/hb-ot-cmap-table.hh b/src/hb-ot-cmap-table.hh
index 1d2265933..1a5408106 100644
--- a/src/hb-ot-cmap-table.hh
+++ b/src/hb-ot-cmap-table.hh
@@ -743,10 +743,11 @@ struct CmapSubtableLongSegmented
 			unsigned num_glyphs) const
   {
     hb_codepoint_t last_end = 0;
-    for (unsigned i = 0; i < this->groups.len; i++)
+    unsigned count = this->groups.len;
+    for (unsigned i = 0; i < count; i++)
     {
-      hb_codepoint_t start = this->groups[i].startCharCode;
-      hb_codepoint_t end = hb_min ((hb_codepoint_t) this->groups[i].endCharCode,
+      hb_codepoint_t start = this->groups.arrayZ[i].startCharCode;
+      hb_codepoint_t end = hb_min ((hb_codepoint_t) this->groups.arrayZ[i].endCharCode,
 				   (hb_codepoint_t) HB_UNICODE_MAX);
       if (unlikely (start > end || start < last_end)) {
         // Range is not in order and is invalid, skip it.
@@ -755,7 +756,7 @@ struct CmapSubtableLongSegmented
       last_end = end;
 
 
-      hb_codepoint_t gid = this->groups[i].glyphID;
+      hb_codepoint_t gid = this->groups.arrayZ[i].glyphID;
       if (!gid)
       {
         if (T::formatNumber == 13) continue;