diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh
index 994a16963..c475d1290 100644
--- a/src/hb-ot-layout-gpos-table.hh
+++ b/src/hb-ot-layout-gpos-table.hh
@@ -1431,9 +1431,7 @@ struct PosLookupSubTable
 
   protected:
   union {
-  struct {
-    USHORT		sub_format;
-  } header;
+  USHORT		sub_format;
   SinglePos		single;
   PairPos		pair;
   CursivePos		cursive;
@@ -1445,7 +1443,7 @@ struct PosLookupSubTable
   ExtensionPos		extension;
   } u;
   public:
-  DEFINE_SIZE_UNION (2, header.sub_format);
+  DEFINE_SIZE_UNION (2, sub_format);
 };
 
 
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index 4c9aac0bb..8a9546b10 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -1131,9 +1131,7 @@ struct SubstLookupSubTable
 
   protected:
   union {
-  struct {
-    USHORT			sub_format;
-  } header;
+  USHORT			sub_format;
   SingleSubst			single;
   MultipleSubst			multiple;
   AlternateSubst		alternate;
@@ -1144,7 +1142,7 @@ struct SubstLookupSubTable
   ReverseChainSingleSubst	reverseChainContextSingle;
   } u;
   public:
-  DEFINE_SIZE_UNION (2, header.sub_format);
+  DEFINE_SIZE_UNION (2, sub_format);
 };