diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c
index 2303a76ec4c..a929b302de0 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c
@@ -881,12 +881,11 @@ static void panel_draw(const bContext *UNUSED(C), Panel *panel)
   PointerRNA ob_ptr;
   PointerRNA *ptr = gpencil_modifier_panel_get_property_pointers(panel, &ob_ptr);
 
-  int mode = RNA_enum_get(ptr, "mode");
+  const int mode = RNA_enum_get(ptr, "mode");
   int time_mode = RNA_enum_get(ptr, "time_mode");
   const bool use_percentage = RNA_boolean_get(ptr, "use_percentage");
 
   uiLayoutSetPropSep(layout, true);
-  RNA_def_enum_funcs(RNA_enum_get(ptr, "time_mode"), prop_gpencil_build_time_mode(mode));
 
   /* First: Build mode and build settings. */
   uiItemR(layout, ptr, "mode", 0, NULL, ICON_NONE);
@@ -923,6 +922,8 @@ static void panel_draw(const bContext *UNUSED(C), Panel *panel)
     case GP_BUILD_TIMEMODE_PERCENTAGE:
       uiItemR(layout, ptr, "percentage_factor", 0, NULL, ICON_NONE);
       break;
+    default:
+      break;
   }
   uiItemS(layout);
   uiItemR(layout, ptr, "object", 0, NULL, ICON_NONE);
diff --git a/source/blender/makesrna/intern/rna_gpencil_modifier.c b/source/blender/makesrna/intern/rna_gpencil_modifier.c
index a0c9c656459..7f00fffeaef 100644
--- a/source/blender/makesrna/intern/rna_gpencil_modifier.c
+++ b/source/blender/makesrna/intern/rna_gpencil_modifier.c
@@ -158,6 +158,25 @@ const EnumPropertyItem rna_enum_object_greasepencil_modifier_type_items[] = {
     {0, NULL, 0, NULL, NULL},
 };
 
+static const EnumPropertyItem gpencil_build_time_mode_items[] = {
+    {GP_BUILD_TIMEMODE_DRAWSPEED,
+     "DRAWSPEED",
+     0,
+     "Natural Drawing Speed",
+     "Use recorded speed multiplied by a factor"},
+    {GP_BUILD_TIMEMODE_FRAMES,
+     "FRAMES",
+     0,
+     "Number of Frames",
+     "Set a fixed number of frames for all build animations"},
+    {GP_BUILD_TIMEMODE_PERCENTAGE,
+     "PERCENTAGE",
+     0,
+     "Percentage Factor",
+     "Set a manual percentage to build"},
+    {0, NULL, 0, NULL, NULL},
+};
+
 #ifndef RNA_RUNTIME
 static const EnumPropertyItem modifier_modify_color_items[] = {
     {GP_MODIFY_COLOR_BOTH, "BOTH", 0, "Stroke & Fill", "Modify fill and stroke colors"},
@@ -925,6 +944,33 @@ static void rna_EnvelopeGpencilModifier_material_set(PointerRNA *ptr,
   rna_GpencilModifier_material_set(ptr, value, ma_target, reports);
 }
 
+const EnumPropertyItem *gpencil_build_time_mode_filter(bContext *UNUSED(C),
+                                                       PointerRNA *ptr,
+                                                       PropertyRNA *prop,
+                                                       bool *r_free)
+{
+
+  GpencilModifierData *md = ptr->data;
+  BuildGpencilModifierData *mmd = (BuildGpencilModifierData *)md;
+  const bool is_concurrent = (mmd->mode == GP_BUILD_MODE_CONCURRENT);
+
+  EnumPropertyItem *item_list = NULL;
+  int totitem = 0;
+
+  for (const EnumPropertyItem *item = gpencil_build_time_mode_items; item->identifier != NULL;
+       item++) {
+    if (is_concurrent && item->identifier == "DRAWSPEED") {
+      continue;
+    }
+    RNA_enum_item_add(&item_list, &totitem, item);
+  }
+
+  RNA_enum_item_end(&item_list, &totitem);
+  *r_free = true;
+
+  return item_list;
+}
+
 #else
 
 static void rna_def_modifier_gpencilnoise(BlenderRNA *brna)
@@ -2395,32 +2441,6 @@ static void rna_def_modifier_gpencilarray(BlenderRNA *brna)
 
   RNA_define_lib_overridable(false);
 }
-const EnumPropertyItem *prop_gpencil_build_time_mode_filter(bContext *UNUSED(C),
-                                                            PointerRNA *ptr,
-                                                            PropertyRNA *prop,
-                                                            bool *r_free)
-{
-  GpencilModifierData *md = ptr->data;
-  BuildGpencilModifierData *mmd = (BuildGpencilModifierData *)md;
-
-  EnumPropertyItem *time_mode_all = (EnumPropertyRNA *)prop;
-  if (mmd->mode != GP_BUILD_MODE_CONCURRENT) {
-    return time_mode_all;
-  }
-
-  EnumPropertyItem *time_mode_filtered = NULL;
-  int items_len = 0;
-  for (const EnumPropertyItem *item = time_mode_all; item->identifier != NULL; item++) {
-    if (item->identifier != "DRAWSPEED") {
-      RNA_enum_item_add(&time_mode_filtered, &items_len, item);
-    }
-  }
-
-  RNA_enum_item_end(&time_mode_filtered, &items_len);
-  *r_free = true;
-
-  return time_mode_filtered;
-}
 
 static void rna_def_modifier_gpencilbuild(BlenderRNA *brna)
 {
@@ -2479,25 +2499,6 @@ static void rna_def_modifier_gpencilbuild(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
-  static EnumPropertyItem prop_gpencil_build_time_mode[] = {
-      {GP_BUILD_TIMEMODE_DRAWSPEED,
-       "DRAWSPEED",
-       0,
-       "Natural Drawing Speed",
-       "Use recorded speed multiplied by a factor"},
-      {GP_BUILD_TIMEMODE_FRAMES,
-       "FRAMES",
-       0,
-       "Number of Frames",
-       "Set a fixed number of frames for all build animations"},
-      {GP_BUILD_TIMEMODE_PERCENTAGE,
-       "PERCENTAGE",
-       0,
-       "Percentage Factor",
-       "Set a manual percentage to build"},
-      {0, NULL, 0, NULL, NULL},
-  };
-
   StructRNA *srna;
   PropertyRNA *prop;
 
@@ -2550,8 +2551,8 @@ static void rna_def_modifier_gpencilbuild(BlenderRNA *brna)
   /* Which time mode to use: Current frames, manual percentage, or drawspeed.  */
   prop = RNA_def_property(srna, "time_mode", PROP_ENUM, PROP_NONE);
   RNA_def_property_enum_sdna(prop, NULL, "time_mode");
-  RNA_def_property_enum_items(prop, prop_gpencil_build_time_mode);
-  RNA_def_property_enum_funcs(prop, NULL, NULL, "prop_gpencil_build_time_mode_filter");
+  RNA_def_property_enum_items(prop, gpencil_build_time_mode_items);
+  RNA_def_property_enum_funcs(prop, NULL, NULL, "gpencil_build_time_mode_filter");
   RNA_def_property_ui_text(
       prop,
       "Timing",