diff --git a/src/hb-ot-var-gvar-table.hh b/src/hb-ot-var-gvar-table.hh
index a95c00560..59aad57e3 100644
--- a/src/hb-ot-var-gvar-table.hh
+++ b/src/hb-ot-var-gvar-table.hh
@@ -121,7 +121,7 @@ struct glyph_variations_t
     unsigned count = plan->new_to_old_gid_list.length;
     bool iup_optimize = false;
 #ifdef HB_EXPERIMENTAL_API
-    iup_optimize = plan->flags & HB_SUBSET_FLAGS_IUP_DELTA_OPT;
+    iup_optimize = plan->flags & HB_SUBSET_FLAGS_OPTIMIZE_IUP_DELTAS;
 #endif
     for (unsigned i = 0; i < count; i++)
     {
diff --git a/src/hb-subset-plan.cc b/src/hb-subset-plan.cc
index 536c98a49..f1909d66f 100644
--- a/src/hb-subset-plan.cc
+++ b/src/hb-subset-plan.cc
@@ -1100,7 +1100,7 @@ _get_instance_glyphs_contour_points (hb_subset_plan_t *plan)
 
 #ifdef HB_EXPERIMENTAL_API
     /* composite new gids are only needed by iup delta optimization */
-    if ((plan->flags & HB_SUBSET_FLAGS_IUP_DELTA_OPT) && glyph.is_composite ())
+    if ((plan->flags & HB_SUBSET_FLAGS_OPTIMIZE_IUP_DELTAS) && glyph.is_composite ())
       plan->composite_new_gids.add (new_gid);
 #endif
   }
diff --git a/src/hb-subset.h b/src/hb-subset.h
index 267af12a8..00b6beae0 100644
--- a/src/hb-subset.h
+++ b/src/hb-subset.h
@@ -76,7 +76,7 @@ typedef struct hb_subset_plan_t hb_subset_plan_t;
  * @HB_SUBSET_FLAGS_IFTB_REQUIREMENTS: If set enforce requirements on the output subset
  * to allow it to be used with incremental font transfer IFTB patches. Primarily,
  * this forces all outline data to use long (32 bit) offsets. Since: EXPERIMENTAL
- * @HB_SUBSET_FLAGS_IUP_DELTA_OPT: If set perform IUP delta optimization on the
+ * @HB_SUBSET_FLAGS_OPTIMIZE_IUP_DELTAS: If set perform IUP delta optimization on the
  * remaining gvar table's deltas. Since: EXPERIMENTAL
  *
  * List of boolean properties that can be configured on the subset input.
@@ -97,7 +97,7 @@ typedef enum { /*< flags >*/
   HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE =        0x00000200u,
 #ifdef HB_EXPERIMENTAL_API
   HB_SUBSET_FLAGS_IFTB_REQUIREMENTS       =  0x00000400u,
-  HB_SUBSET_FLAGS_IUP_DELTA_OPT           =  0x00000800u,
+  HB_SUBSET_FLAGS_OPTIMIZE_IUP_DELTAS	  =  0x00000800u,
 #endif
 } hb_subset_flags_t;
 
diff --git a/util/hb-subset.cc b/util/hb-subset.cc
index ff602b6d0..73d00368d 100644
--- a/util/hb-subset.cc
+++ b/util/hb-subset.cc
@@ -963,7 +963,7 @@ subset_main_t::add_options ()
      "If set preprocesses the face with the add accelerator option before actually subsetting.", nullptr},
 #ifdef HB_EXPERIMENTAL_API
     {"iftb-requirements",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_IFTB_REQUIREMENTS>,	"Enforce requirements needed to use the subset with incremental font transfer IFTB patches.", nullptr},
-    {"optimize",		0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_IUP_DELTA_OPT>,		"Perform IUP delta optimization on the resulting gvar table's deltas", nullptr},
+    {"optimize",		0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_OPTIMIZE_IUP_DELTAS>,		"Perform IUP delta optimization on the resulting gvar table's deltas", nullptr},
 #endif
     {nullptr}
   };