diff --git a/ginfo.c b/ginfo.c
index 3de0cf590..a3813d641 100644
--- a/ginfo.c
+++ b/ginfo.c
@@ -1112,6 +1112,24 @@ g_struct_info_find_method (GIStructInfo *info,
   return find_method (base, offset, blob->n_methods, name);
 }
 
+gsize
+g_struct_info_get_size (GIStructInfo *info)
+{
+  GIBaseInfo *base = (GIBaseInfo *)info;
+  StructBlob *blob = (StructBlob *)&base->typelib->data[base->offset];
+
+  return blob->size;
+}
+
+gsize
+g_struct_info_get_alignment (GIStructInfo *info)
+{
+  GIBaseInfo *base = (GIBaseInfo *)info;
+  StructBlob *blob = (StructBlob *)&base->typelib->data[base->offset];
+
+  return blob->alignment;
+}
+
 gint
 g_enum_info_get_n_values (GIEnumInfo *info)
 {
@@ -1887,3 +1905,20 @@ g_union_info_find_method (GIUnionInfo *info,
   return find_method (base, offset, blob->n_functions, name);
 }
 
+gsize
+g_union_info_get_size (GIUnionInfo *info)
+{
+  GIBaseInfo *base = (GIBaseInfo *)info;
+  UnionBlob *blob = (UnionBlob *)&base->typelib->data[base->offset];
+
+  return blob->size;
+}
+
+gsize
+g_union_info_get_alignment (GIUnionInfo *info)
+{
+  GIBaseInfo *base = (GIBaseInfo *)info;
+  UnionBlob *blob = (UnionBlob *)&base->typelib->data[base->offset];
+
+  return blob->alignment;
+}
diff --git a/girepository.h b/girepository.h
index fc5768c5f..a671cb5c8 100644
--- a/girepository.h
+++ b/girepository.h
@@ -377,6 +377,8 @@ GIConstantInfo *       g_union_info_get_discriminator      (GIUnionInfo *info,
 					                    gint         n);
 GIFunctionInfo *       g_union_info_find_method    (GIUnionInfo *info,
                                                     const gchar *name);
+gsize                  g_union_info_get_size       (GIUnionInfo *info);
+gsize                  g_union_info_get_alignment  (GIUnionInfo *info);
 
 
 /* GIStructInfo */
@@ -388,6 +390,8 @@ GIFunctionInfo *       g_struct_info_get_method    (GIStructInfo *info,
 						    gint         n);
 GIFunctionInfo *       g_struct_info_find_method   (GIStructInfo *info,
 						    const gchar *name);
+gsize                  g_struct_info_get_size      (GIStructInfo *info);
+gsize                  g_struct_info_get_alignment (GIStructInfo *info);
 
 /* GIRegisteredTypeInfo */
 
diff --git a/girmodule.c b/girmodule.c
index 1b7c3048c..1b26f3de4 100644
--- a/girmodule.c
+++ b/girmodule.c
@@ -222,10 +222,10 @@ g_ir_module_build_typelib (GIrModule  *module,
   header->annotation_blob_size = 12;
   header->signature_blob_size = 8;
   header->enum_blob_size = 20;
-  header->struct_blob_size = 20;
+  header->struct_blob_size = 24;
   header->object_blob_size = 32;
   header->interface_blob_size = 28;
-  header->union_blob_size = 28;
+  header->union_blob_size = 32;
 
   /* fill in directory and content */
   entry = (DirEntry *)&data[header->directory];
diff --git a/girnode.c b/girnode.c
index 8851df066..9f809d4be 100644
--- a/girnode.c
+++ b/girnode.c
@@ -469,7 +469,7 @@ g_ir_node_get_size (GIrNode *node)
       {
 	GIrNodeStruct *struct_ = (GIrNodeStruct *)node;
 
-	size = 20;
+	size = 24;
 	for (l = struct_->members; l; l = l->next)
 	  size += g_ir_node_get_size ((GIrNode *)l->data);
       }
@@ -479,7 +479,7 @@ g_ir_node_get_size (GIrNode *node)
       {
 	GIrNodeBoxed *boxed = (GIrNodeBoxed *)node;
 
-	size = 20;
+	size = 24;
 	for (l = boxed->members; l; l = l->next)
 	  size += g_ir_node_get_size ((GIrNode *)l->data);
       }
@@ -517,7 +517,7 @@ g_ir_node_get_size (GIrNode *node)
       {
 	GIrNodeUnion *union_ = (GIrNodeUnion *)node;
 
-	size = 28;
+	size = 32;
 	for (l = union_->members; l; l = l->next)
 	  size += g_ir_node_get_size ((GIrNode *)l->data);
 	for (l = union_->discriminators; l; l = l->next)
@@ -707,7 +707,7 @@ g_ir_node_get_full_size_internal (GIrNode *parent,
       {
 	GIrNodeStruct *struct_ = (GIrNodeStruct *)node;
 
-	size = 20;
+	size = 24;
 	size += ALIGN_VALUE (strlen (node->name) + 1, 4);
 	if (struct_->gtype_name)
 	  size += ALIGN_VALUE (strlen (struct_->gtype_name) + 1, 4);
@@ -722,7 +722,7 @@ g_ir_node_get_full_size_internal (GIrNode *parent,
       {
 	GIrNodeBoxed *boxed = (GIrNodeBoxed *)node;
 
-	size = 20;
+	size = 24;
 	size += ALIGN_VALUE (strlen (node->name) + 1, 4);
 	if (boxed->gtype_name)
 	  {
@@ -814,7 +814,7 @@ g_ir_node_get_full_size_internal (GIrNode *parent,
       {
 	GIrNodeUnion *union_ = (GIrNodeUnion *)node;
 
-	size = 28;
+	size = 32;
 	size += ALIGN_VALUE (strlen (node->name) + 1, 4);
 	if (union_->gtype_name)
 	  size += ALIGN_VALUE (strlen (union_->gtype_name) + 1, 4);
@@ -1789,6 +1789,9 @@ g_ir_node_build_typelib (GIrNode    *node,
 	blob->deprecated = struct_->deprecated;
 	blob->reserved = 0;
 	blob->name = write_string (node->name, strings, data, offset2);
+	blob->alignment = struct_->alignment;
+	blob->size = struct_->size;
+
 	if (struct_->gtype_name)
 	  {
 	    blob->unregistered = FALSE;
@@ -1805,7 +1808,7 @@ g_ir_node_build_typelib (GIrNode    *node,
 	blob->n_fields = 0;
 	blob->n_methods = 0;
 
-	*offset += 20; 
+	*offset += 24; 
 
 	members = g_list_copy (struct_->members);
 
@@ -1836,11 +1839,13 @@ g_ir_node_build_typelib (GIrNode    *node,
 	blob->name = write_string (node->name, strings, data, offset2);
 	blob->gtype_name = write_string (boxed->gtype_name, strings, data, offset2);
 	blob->gtype_init = write_string (boxed->gtype_init, strings, data, offset2);
+	blob->alignment = boxed->alignment;
+	blob->size = boxed->size;
 
 	blob->n_fields = 0;
 	blob->n_methods = 0;
 
-	*offset += 20; 
+	*offset += 24; 
 
 	members = g_list_copy (boxed->members);
 
@@ -1868,6 +1873,8 @@ g_ir_node_build_typelib (GIrNode    *node,
 	blob->deprecated = union_->deprecated;
  	blob->reserved = 0;
 	blob->name = write_string (node->name, strings, data, offset2);
+	blob->alignment = union_->alignment;
+	blob->size = union_->size;
 	if (union_->gtype_name)
 	  {
 	    blob->unregistered = FALSE;
@@ -1888,7 +1895,7 @@ g_ir_node_build_typelib (GIrNode    *node,
 
 	if (union_->discriminator_type)
 	  {
-	    *offset += 24;
+	    *offset += 28;
 	    blob->discriminated = TRUE;
 	    g_ir_node_build_typelib ((GIrNode *)union_->discriminator_type, 
 				     module, modules, strings, types,
@@ -1896,7 +1903,7 @@ g_ir_node_build_typelib (GIrNode    *node,
 	  }
 	else 
 	  {
-	    *offset += 28;
+	    *offset += 32;
 	    blob->discriminated = FALSE;
 	    blob->discriminator_type.offset = 0;
 	  }
diff --git a/gtypelib.c b/gtypelib.c
index be470a4b0..8472195fe 100644
--- a/gtypelib.c
+++ b/gtypelib.c
@@ -168,7 +168,7 @@ g_typelib_check_sanity (void)
   CHECK_SIZE (ValueBlob, 12);
   CHECK_SIZE (FieldBlob, 12);
   CHECK_SIZE (RegisteredTypeBlob, 16);
-  CHECK_SIZE (StructBlob, 20);
+  CHECK_SIZE (StructBlob, 24);
   CHECK_SIZE (EnumBlob, 20);
   CHECK_SIZE (PropertyBlob, 12);
   CHECK_SIZE (SignalBlob, 12);
@@ -177,7 +177,7 @@ g_typelib_check_sanity (void)
   CHECK_SIZE (InterfaceBlob, 28);
   CHECK_SIZE (ConstantBlob, 20);
   CHECK_SIZE (AnnotationBlob, 12);
-  CHECK_SIZE (UnionBlob, 28);
+  CHECK_SIZE (UnionBlob, 32);
 #undef CHECK_SIZE
 
   g_assert (size_check_ok);
@@ -320,10 +320,10 @@ validate_header (ValidateContext  *ctx,
       header->annotation_blob_size != 12 ||
       header->signature_blob_size != 8 ||
       header->enum_blob_size != 20 ||
-      header->struct_blob_size != 20 ||
+      header->struct_blob_size != 24 ||
       header->object_blob_size != 32 ||
       header->interface_blob_size != 28 ||
-      header->union_blob_size != 28)
+      header->union_blob_size != 32)
     {
       g_set_error (error,
 		   G_TYPELIB_ERROR,
diff --git a/gtypelib.h b/gtypelib.h
index 458d429d1..1b2b8934a 100644
--- a/gtypelib.h
+++ b/gtypelib.h
@@ -295,13 +295,16 @@ typedef struct
 
   guint16   deprecated   : 1;
   guint16   unregistered : 1;
-  guint16   reserved     :14;
+  guint16   alignment    : 6;
+  guint16   reserved     : 8;
 
   guint32   name;
 
   guint32   gtype_name;
   guint32   gtype_init;
 
+  guint32   size;
+
   guint16   n_fields;
   guint16   n_methods;
 
@@ -318,12 +321,15 @@ typedef struct
   guint16      deprecated    : 1;
   guint16      unregistered  : 1;
   guint16      discriminated : 1;
-  guint16      reserved      :13;
+  guint16      alignment     : 6;
+  guint16      reserved      : 7;
   guint32      name;
 
   guint32      gtype_name;
   guint32      gtype_init;
 
+  guint32      size;
+
   guint16      n_fields;
   guint16      n_functions;