diff --git a/source/blender/io/alembic/ABC_alembic.h b/source/blender/io/alembic/ABC_alembic.h
index ba430752b29..ddf75aa3258 100644
--- a/source/blender/io/alembic/ABC_alembic.h
+++ b/source/blender/io/alembic/ABC_alembic.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_ALEMBIC_H__
-#define __ABC_ALEMBIC_H__
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -133,5 +131,3 @@ struct CacheReader *CacheReader_open_alembic_object(struct AbcArchiveHandle *han
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* __ABC_ALEMBIC_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_exporter.h b/source/blender/io/alembic/exporter/abc_exporter.h
index f3ca1710e33..af30f2ceb50 100644
--- a/source/blender/io/alembic/exporter/abc_exporter.h
+++ b/source/blender/io/alembic/exporter/abc_exporter.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_EXPORTER_H__
-#define __ABC_EXPORTER_H__
-
 #include <Alembic/Abc/All.h>
 #include <map>
 #include <set>
@@ -131,5 +129,3 @@ class AbcExporter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_EXPORTER_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_archive.h b/source/blender/io/alembic/exporter/abc_writer_archive.h
index 81dd387e720..db13dc0ec92 100644
--- a/source/blender/io/alembic/exporter/abc_writer_archive.h
+++ b/source/blender/io/alembic/exporter/abc_writer_archive.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_ARCHIVE_H__
-#define __ABC_WRITER_ARCHIVE_H__
-
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcCoreOgawa/All.h>
 
@@ -54,5 +52,3 @@ class ArchiveWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_ARCHIVE_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_camera.h b/source/blender/io/alembic/exporter/abc_writer_camera.h
index 44b80984411..befa1e24551 100644
--- a/source/blender/io/alembic/exporter/abc_writer_camera.h
+++ b/source/blender/io/alembic/exporter/abc_writer_camera.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_CAMERA_H__
-#define __ABC_WRITER_CAMERA_H__
-
 #include "abc_writer_object.h"
 
 /* ************************************************************************** */
@@ -49,5 +47,3 @@ class AbcCameraWriter : public AbcObjectWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_CAMERA_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_curves.h b/source/blender/io/alembic/exporter/abc_writer_curves.h
index 35fb063c4a5..d12ebc46a22 100644
--- a/source/blender/io/alembic/exporter/abc_writer_curves.h
+++ b/source/blender/io/alembic/exporter/abc_writer_curves.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_CURVES_H__
-#define __ABC_WRITER_CURVES_H__
-
 #include "abc_writer_mesh.h"
 #include "abc_writer_object.h"
 
@@ -59,5 +57,3 @@ class AbcCurveMeshWriter : public AbcGenericMeshWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_CURVES_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_hair.h b/source/blender/io/alembic/exporter/abc_writer_hair.h
index b6860926d44..d7831684a12 100644
--- a/source/blender/io/alembic/exporter/abc_writer_hair.h
+++ b/source/blender/io/alembic/exporter/abc_writer_hair.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_HAIR_H__
-#define __ABC_WRITER_HAIR_H__
-
 #include "abc_writer_object.h"
 
 struct Mesh;
@@ -67,5 +65,3 @@ class AbcHairWriter : public AbcObjectWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_HAIR_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_mball.h b/source/blender/io/alembic/exporter/abc_writer_mball.h
index f527b2b02a0..d632f0bd410 100644
--- a/source/blender/io/alembic/exporter/abc_writer_mball.h
+++ b/source/blender/io/alembic/exporter/abc_writer_mball.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_MBALL_H__
-#define __ABC_WRITER_MBALL_H__
-
 #include "abc_writer_mesh.h"
 #include "abc_writer_object.h"
 
@@ -60,5 +58,3 @@ class AbcMBallWriter : public AbcGenericMeshWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_MBALL_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_mesh.h b/source/blender/io/alembic/exporter/abc_writer_mesh.h
index e4095758ba9..412c5530b32 100644
--- a/source/blender/io/alembic/exporter/abc_writer_mesh.h
+++ b/source/blender/io/alembic/exporter/abc_writer_mesh.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_MESH_H__
-#define __ABC_WRITER_MESH_H__
-
 #include "abc_writer_object.h"
 #include "intern/abc_customdata.h"
 
@@ -95,5 +93,3 @@ class AbcMeshWriter : public AbcGenericMeshWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_MESH_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_nurbs.h b/source/blender/io/alembic/exporter/abc_writer_nurbs.h
index 006024c4d2f..b2a9cf1b786 100644
--- a/source/blender/io/alembic/exporter/abc_writer_nurbs.h
+++ b/source/blender/io/alembic/exporter/abc_writer_nurbs.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_NURBS_H__
-#define __ABC_WRITER_NURBS_H__
-
 #include "abc_writer_object.h"
 
 namespace blender {
@@ -46,5 +44,3 @@ class AbcNurbsWriter : public AbcObjectWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_NURBS_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_object.h b/source/blender/io/alembic/exporter/abc_writer_object.h
index 0496c6a3624..7f8e8735812 100644
--- a/source/blender/io/alembic/exporter/abc_writer_object.h
+++ b/source/blender/io/alembic/exporter/abc_writer_object.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_OBJECT_H__
-#define __ABC_WRITER_OBJECT_H__
-
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcGeom/All.h>
 
@@ -73,5 +71,3 @@ class AbcObjectWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_OBJECT_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_points.h b/source/blender/io/alembic/exporter/abc_writer_points.h
index 5763808d6a7..7e8a3eaadcd 100644
--- a/source/blender/io/alembic/exporter/abc_writer_points.h
+++ b/source/blender/io/alembic/exporter/abc_writer_points.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_POINTS_H__
-#define __ABC_WRITER_POINTS_H__
-
 #include "abc_writer_object.h"
 #include "intern/abc_customdata.h"
 
@@ -53,5 +51,3 @@ class AbcPointsWriter : public AbcObjectWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_POINTS_H__ */
diff --git a/source/blender/io/alembic/exporter/abc_writer_transform.h b/source/blender/io/alembic/exporter/abc_writer_transform.h
index af50929a963..fc997d77f4c 100644
--- a/source/blender/io/alembic/exporter/abc_writer_transform.h
+++ b/source/blender/io/alembic/exporter/abc_writer_transform.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_WRITER_TRANSFORM_H__
-#define __ABC_WRITER_TRANSFORM_H__
-
 #include "abc_writer_object.h"
 
 #include <Alembic/AbcGeom/All.h>
@@ -64,5 +62,3 @@ class AbcTransformWriter : public AbcObjectWriter {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_WRITER_TRANSFORM_H__ */
diff --git a/source/blender/io/alembic/intern/abc_customdata.h b/source/blender/io/alembic/intern/abc_customdata.h
index a5f480d48c3..8f4accb70dc 100644
--- a/source/blender/io/alembic/intern/abc_customdata.h
+++ b/source/blender/io/alembic/intern/abc_customdata.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_CUSTOMDATA_H__
-#define __ABC_CUSTOMDATA_H__
-
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcGeom/All.h>
 
@@ -118,5 +116,3 @@ void read_custom_data(const std::string &iobject_full_name,
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_CUSTOMDATA_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_archive.h b/source/blender/io/alembic/intern/abc_reader_archive.h
index 6f3478aa14e..aea62b46cce 100644
--- a/source/blender/io/alembic/intern/abc_reader_archive.h
+++ b/source/blender/io/alembic/intern/abc_reader_archive.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_ARCHIVE_H__
-#define __ABC_READER_ARCHIVE_H__
-
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcCoreOgawa/All.h>
 
@@ -57,5 +55,3 @@ class ArchiveReader {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_ARCHIVE_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_camera.h b/source/blender/io/alembic/intern/abc_reader_camera.h
index 3aa905e36c4..b733269407b 100644
--- a/source/blender/io/alembic/intern/abc_reader_camera.h
+++ b/source/blender/io/alembic/intern/abc_reader_camera.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_CAMERA_H__
-#define __ABC_READER_CAMERA_H__
-
 #include "abc_reader_object.h"
 
 namespace blender {
@@ -44,5 +42,3 @@ class AbcCameraReader : public AbcObjectReader {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_CAMERA_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_curves.h b/source/blender/io/alembic/intern/abc_reader_curves.h
index bef5bec2e74..7488adb9b24 100644
--- a/source/blender/io/alembic/intern/abc_reader_curves.h
+++ b/source/blender/io/alembic/intern/abc_reader_curves.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_CURVES_H__
-#define __ABC_READER_CURVES_H__
-
 #include "abc_reader_mesh.h"
 #include "abc_reader_object.h"
 
@@ -60,5 +58,3 @@ class AbcCurveReader : public AbcObjectReader {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_CURVES_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_mesh.h b/source/blender/io/alembic/intern/abc_reader_mesh.h
index 6acfc057151..363a74b8b5f 100644
--- a/source/blender/io/alembic/intern/abc_reader_mesh.h
+++ b/source/blender/io/alembic/intern/abc_reader_mesh.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_MESH_H__
-#define __ABC_READER_MESH_H__
-
 #include "abc_customdata.h"
 #include "abc_reader_object.h"
 
@@ -90,5 +88,3 @@ CDStreamConfig get_config(struct Mesh *mesh);
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_MESH_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_nurbs.h b/source/blender/io/alembic/intern/abc_reader_nurbs.h
index 49840e49bec..738da82885d 100644
--- a/source/blender/io/alembic/intern/abc_reader_nurbs.h
+++ b/source/blender/io/alembic/intern/abc_reader_nurbs.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_NURBS_H__
-#define __ABC_READER_NURBS_H__
-
 #include "abc_reader_object.h"
 
 namespace blender {
@@ -44,5 +42,3 @@ class AbcNurbsReader : public AbcObjectReader {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_NURBS_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_object.h b/source/blender/io/alembic/intern/abc_reader_object.h
index d8e0e57f2f9..0bde60b06b5 100644
--- a/source/blender/io/alembic/intern/abc_reader_object.h
+++ b/source/blender/io/alembic/intern/abc_reader_object.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_OBJECT_H__
-#define __ABC_READER_OBJECT_H__
-
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcGeom/All.h>
 
@@ -173,5 +171,3 @@ Imath::M44d get_matrix(const Alembic::AbcGeom::IXformSchema &schema, const float
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_OBJECT_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_points.h b/source/blender/io/alembic/intern/abc_reader_points.h
index 91ddcf31de1..8a970ac35b3 100644
--- a/source/blender/io/alembic/intern/abc_reader_points.h
+++ b/source/blender/io/alembic/intern/abc_reader_points.h
@@ -16,14 +16,12 @@
  * The Original Code is Copyright (C) 2016 Kévin Dietrich.
  * All rights reserved.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_POINTS_H__
-#define __ABC_READER_POINTS_H__
-
 #include "abc_customdata.h"
 #include "abc_reader_object.h"
 
@@ -58,5 +56,3 @@ void read_points_sample(const Alembic::AbcGeom::IPointsSchema &schema,
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_POINTS_H__ */
diff --git a/source/blender/io/alembic/intern/abc_reader_transform.h b/source/blender/io/alembic/intern/abc_reader_transform.h
index 57e1f9b2334..812d3bdfc92 100644
--- a/source/blender/io/alembic/intern/abc_reader_transform.h
+++ b/source/blender/io/alembic/intern/abc_reader_transform.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_READER_TRANSFORM_H__
-#define __ABC_READER_TRANSFORM_H__
-
 #include "abc_reader_object.h"
 
 #include <Alembic/AbcGeom/All.h>
@@ -46,5 +44,3 @@ class AbcEmptyReader : public AbcObjectReader {
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_READER_TRANSFORM_H__ */
diff --git a/source/blender/io/alembic/intern/abc_util.h b/source/blender/io/alembic/intern/abc_util.h
index fbad1cce306..5353d7a422b 100644
--- a/source/blender/io/alembic/intern/abc_util.h
+++ b/source/blender/io/alembic/intern/abc_util.h
@@ -13,14 +13,12 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#pragma once
 
 /** \file
  * \ingroup balembic
  */
 
-#ifndef __ABC_UTIL_H__
-#define __ABC_UTIL_H__
-
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcGeom/All.h>
 
@@ -172,5 +170,3 @@ std::ostream &operator<<(std::ostream &os, const SimpleLogger &logger);
 }  // namespace alembic
 }  // namespace io
 }  // namespace blender
-
-#endif /* __ABC_UTIL_H__ */