diff --git a/source/blender/blenkernel/BKE_grease_pencil.hh b/source/blender/blenkernel/BKE_grease_pencil.hh
index 4f23f247b33..37a3420affe 100644
--- a/source/blender/blenkernel/BKE_grease_pencil.hh
+++ b/source/blender/blenkernel/BKE_grease_pencil.hh
@@ -729,7 +729,9 @@ namespace convert {
 void legacy_gpencil_frame_to_grease_pencil_drawing(const bGPDframe &gpf,
                                                    const ListBase &vertex_group_names,
                                                    GreasePencilDrawing &r_drawing);
-void legacy_gpencil_to_grease_pencil(Main &main, GreasePencil &grease_pencil, bGPdata &gpd);
+void legacy_gpencil_to_grease_pencil(Main &bmain, GreasePencil &grease_pencil, bGPdata &gpd);
+
+void legacy_gpencil_object(Main &bmain, Object &object);
 
 }  // namespace convert
 }  // namespace greasepencil
diff --git a/source/blender/blenkernel/intern/grease_pencil_convert_legacy.cc b/source/blender/blenkernel/intern/grease_pencil_convert_legacy.cc
index 8220396c796..548407130cd 100644
--- a/source/blender/blenkernel/intern/grease_pencil_convert_legacy.cc
+++ b/source/blender/blenkernel/intern/grease_pencil_convert_legacy.cc
@@ -10,7 +10,9 @@
 #include "BKE_curves.hh"
 #include "BKE_deform.hh"
 #include "BKE_grease_pencil.hh"
+#include "BKE_lib_id.hh"
 #include "BKE_material.h"
+#include "BKE_object.hh"
 
 #include "BLI_color.hh"
 #include "BLI_listbase.h"
@@ -334,4 +336,24 @@ void legacy_gpencil_to_grease_pencil(Main &bmain, GreasePencil &grease_pencil, b
   BKE_id_materials_copy(&bmain, &gpd.id, &grease_pencil.id);
 }
 
+void legacy_gpencil_object(Main &bmain, Object &object)
+{
+  bGPdata *gpd = static_cast<bGPdata *>(object.data);
+
+  GreasePencil *new_grease_pencil = static_cast<GreasePencil *>(
+      BKE_id_new(&bmain, ID_GP, gpd->id.name + 2));
+  object.data = new_grease_pencil;
+  object.type = OB_GREASE_PENCIL;
+
+  /* NOTE: Could also use #BKE_id_free_us, to also free the legacy GP if not used anymore? */
+  id_us_min(&gpd->id);
+  /* No need to increase usercount of `new_grease_pencil`, since ID creation already set it
+   * to 1. */
+
+  legacy_gpencil_to_grease_pencil(bmain, *new_grease_pencil, *gpd);
+
+  BKE_object_free_derived_caches(&object);
+  BKE_object_free_modifiers(&object, 0);
+}
+
 }  // namespace blender::bke::greasepencil::convert
diff --git a/source/blender/editors/object/object_add.cc b/source/blender/editors/object/object_add.cc
index e7ee36c974f..39755905cd1 100644
--- a/source/blender/editors/object/object_add.cc
+++ b/source/blender/editors/object/object_add.cc
@@ -3222,8 +3222,6 @@ static int object_convert_exec(bContext *C, wmOperator *op)
     {
       ob->flag |= OB_DONE;
 
-      bGPdata *gpd = static_cast<bGPdata *>(ob->data);
-
       if (keep_original) {
         BLI_assert_unreachable();
       }
@@ -3231,21 +3229,7 @@ static int object_convert_exec(bContext *C, wmOperator *op)
         newob = ob;
       }
 
-      GreasePencil *new_grease_pencil = static_cast<GreasePencil *>(
-          BKE_id_new(bmain, ID_GP, gpd->id.name + 2));
-      newob->data = new_grease_pencil;
-      newob->type = OB_GREASE_PENCIL;
-
-      /* NOTE: Could also use #BKE_id_free_us, to also free the legacy GP if not used anymore? */
-      id_us_min(&gpd->id);
-      /* No need to increase usercount of `new_grease_pencil`, since ID creation already set it
-       * to 1. */
-
-      bke::greasepencil::convert::legacy_gpencil_to_grease_pencil(
-          *bmain, *new_grease_pencil, *gpd);
-
-      BKE_object_free_derived_caches(newob);
-      BKE_object_free_modifiers(newob, 0);
+      bke::greasepencil::convert::legacy_gpencil_object(*bmain, *newob);
     }
     else if (target == OB_CURVES) {
       ob->flag |= OB_DONE;