diff --git a/libgimpconfig/gimpcolorconfig.h b/libgimpconfig/gimpcolorconfig.h
index e871c75a14..39c1bf7053 100644
--- a/libgimpconfig/gimpcolorconfig.h
+++ b/libgimpconfig/gimpcolorconfig.h
@@ -19,16 +19,18 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_COLOR_CONFIG_H__
-#define __GIMP_COLOR_CONFIG_H__
-
 
 #define GIMP_TYPE_COLOR_CONFIG (gimp_color_config_get_type ())
-G_DECLARE_FINAL_TYPE (GimpColorConfig, gimp_color_config, GIMP, COLOR_CONFIG, GObject)
+G_DECLARE_FINAL_TYPE (GimpColorConfig,
+                      gimp_color_config,
+                      GIMP, COLOR_CONFIG,
+                      GObject)
 
 
 GimpColorManagementMode
@@ -58,5 +60,3 @@ GimpColorProfile * gimp_color_config_get_display_color_profile    (GimpColorConf
 GimpColorProfile * gimp_color_config_get_simulation_color_profile (GimpColorConfig  *config,
                                                                    GError          **error);
 
-
-#endif /* GIMP_COLOR_CONFIG_H__ */
diff --git a/libgimpconfig/gimpconfig-deserialize.h b/libgimpconfig/gimpconfig-deserialize.h
index 271a20d301..1671ded830 100644
--- a/libgimpconfig/gimpconfig-deserialize.h
+++ b/libgimpconfig/gimpconfig-deserialize.h
@@ -19,13 +19,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_DESERIALIZE_H__
-#define __GIMP_CONFIG_DESERIALIZE_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -38,7 +37,4 @@ GTokenType  gimp_config_deserialize_property   (GimpConfig *config,
                                                 GScanner   *scanner,
                                                 gint        nest_level);
 
-
 G_END_DECLS
-
-#endif /* __GIMP_CONFIG_DESERIALIZE_H__ */
diff --git a/libgimpconfig/gimpconfig-error.h b/libgimpconfig/gimpconfig-error.h
index a20884e37e..b88d7d002c 100644
--- a/libgimpconfig/gimpconfig-error.h
+++ b/libgimpconfig/gimpconfig-error.h
@@ -18,13 +18,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_ERROR_H__
-#define __GIMP_CONFIG_ERROR_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -51,9 +50,7 @@ typedef enum
 
 #define GIMP_CONFIG_ERROR (gimp_config_error_quark ())
 
-GQuark        gimp_config_error_quark   (void) G_GNUC_CONST;
-
+GQuark   gimp_config_error_quark (void) G_GNUC_CONST;
 
 G_END_DECLS
 
-#endif  /* __GIMP_CONFIG_ERROR_H__ */
diff --git a/libgimpconfig/gimpconfig-iface.h b/libgimpconfig/gimpconfig-iface.h
index c142ee6c52..6f0cf8b7cd 100644
--- a/libgimpconfig/gimpconfig-iface.h
+++ b/libgimpconfig/gimpconfig-iface.h
@@ -19,19 +19,23 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_IFACE_H__
-#define __GIMP_CONFIG_IFACE_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
 
+
 #define GIMP_TYPE_CONFIG (gimp_config_get_type ())
-G_DECLARE_INTERFACE (GimpConfig, gimp_config, GIMP, CONFIG, GObject)
+G_DECLARE_INTERFACE (GimpConfig,
+                     gimp_config,
+                     GIMP, CONFIG,
+                     GObject)
+
 
 struct _GimpConfigInterface
 {
@@ -129,7 +133,4 @@ gboolean   gimp_config_copy                  (GimpConfig          *src,
                                               GimpConfig          *dest,
                                               GParamFlags          flags);
 
-
 G_END_DECLS
-
-#endif  /* __GIMP_CONFIG_IFACE_H__ */
diff --git a/libgimpconfig/gimpconfig-params.h b/libgimpconfig/gimpconfig-params.h
index a11175d769..5ae0a19a93 100644
--- a/libgimpconfig/gimpconfig-params.h
+++ b/libgimpconfig/gimpconfig-params.h
@@ -20,13 +20,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_PARAMS_H__
-#define __GIMP_CONFIG_PARAMS_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -228,7 +227,4 @@ G_BEGIN_DECLS
 
 GParamSpec * gimp_config_param_spec_duplicate (GParamSpec *pspec);
 
-
 G_END_DECLS
-
-#endif /* __GIMP_CONFIG_PARAMS_H__ */
diff --git a/libgimpconfig/gimpconfig-path.h b/libgimpconfig/gimpconfig-path.h
index f6dff2a1aa..dd9710fb45 100644
--- a/libgimpconfig/gimpconfig-path.h
+++ b/libgimpconfig/gimpconfig-path.h
@@ -19,13 +19,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_PATH_H__
-#define __GIMP_CONFIG_PATH_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -103,7 +102,5 @@ gchar             * gimp_config_build_writable_path  (const gchar  *name) G_GNUC
 gchar             * gimp_config_build_plug_in_path   (const gchar  *name) G_GNUC_MALLOC;
 gchar             * gimp_config_build_system_path    (const gchar  *name) G_GNUC_MALLOC;
 
-
 G_END_DECLS
 
-#endif /* __GIMP_CONFIG_PATH_H__ */
diff --git a/libgimpconfig/gimpconfig-register.h b/libgimpconfig/gimpconfig-register.h
index 9cfd722a45..e7e8608b5d 100644
--- a/libgimpconfig/gimpconfig-register.h
+++ b/libgimpconfig/gimpconfig-register.h
@@ -19,13 +19,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_REGISTER_H__
-#define __GIMP_CONFIG_REGISTER_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -36,7 +35,4 @@ GType   gimp_config_type_register (GType         parent_type,
                                    GParamSpec  **pspecs,
                                    gint          n_pspecs);
 
-
 G_END_DECLS
-
-#endif /* __GIMP_CONFIG_REGISTER_H__ */
diff --git a/libgimpconfig/gimpconfig-serialize.h b/libgimpconfig/gimpconfig-serialize.h
index c25ab3b391..58de1ddfb3 100644
--- a/libgimpconfig/gimpconfig-serialize.h
+++ b/libgimpconfig/gimpconfig-serialize.h
@@ -19,13 +19,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_SERIALIZE_H__
-#define __GIMP_CONFIG_SERIALIZE_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -46,7 +45,5 @@ gboolean  gimp_config_serialize_value              (const GValue     *value,
                                                     GString          *str,
                                                     gboolean          escaped);
 
-
 G_END_DECLS
 
-#endif /* __GIMP_CONFIG_SERIALIZE_H__ */
diff --git a/libgimpconfig/gimpconfig-utils.h b/libgimpconfig/gimpconfig-utils.h
index 6975b64170..f19cee39ad 100644
--- a/libgimpconfig/gimpconfig-utils.h
+++ b/libgimpconfig/gimpconfig-utils.h
@@ -19,13 +19,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_UTILS_H__
-#define __GIMP_CONFIG_UTILS_H__
-
 G_BEGIN_DECLS
 
 /* For information look into the C source or the html documentation */
@@ -46,7 +45,4 @@ void       gimp_config_reset_property        (GObject      *object,
 void       gimp_config_string_append_escaped (GString      *string,
                                               const gchar  *val);
 
-
 G_END_DECLS
-
-#endif  /* __GIMP_CONFIG_UTILS_H__ */
diff --git a/libgimpconfig/gimpconfig.h b/libgimpconfig/gimpconfig.h
index 43cbf37ddb..7950522a08 100644
--- a/libgimpconfig/gimpconfig.h
+++ b/libgimpconfig/gimpconfig.h
@@ -16,8 +16,7 @@
  * <https://www.gnu.org/licenses/>.
  */
 
-#ifndef __GIMP_CONFIG_H__
-#define __GIMP_CONFIG_H__
+#pragma once
 
 #include <gegl.h>
 
@@ -41,5 +40,3 @@
 #include <libgimpconfig/gimpcolorconfig.h>
 
 #undef __GIMP_CONFIG_H_INSIDE__
-
-#endif  /* __GIMP_CONFIG_H__ */
diff --git a/libgimpconfig/gimpconfigenums.h b/libgimpconfig/gimpconfigenums.h
index 562085021c..0eb9d37156 100644
--- a/libgimpconfig/gimpconfigenums.h
+++ b/libgimpconfig/gimpconfigenums.h
@@ -19,8 +19,7 @@
  * <https://www.gnu.org/licenses/>.
  */
 
-#ifndef __GIMP_CONFIG_ENUMS_H__
-#define __GIMP_CONFIG_ENUMS_H__
+#pragma once
 
 
 #define GIMP_TYPE_COLOR_MANAGEMENT_MODE (gimp_color_management_mode_get_type ())
@@ -63,6 +62,3 @@ typedef enum
   GIMP_COLOR_RENDERING_INTENT_SATURATION,            /*< desc="Saturation"            >*/
   GIMP_COLOR_RENDERING_INTENT_ABSOLUTE_COLORIMETRIC  /*< desc="Absolute colorimetric" >*/
 } GimpColorRenderingIntent;
-
-
-#endif /* __GIMP_CONFIG_ENUMS_H__ */
diff --git a/libgimpconfig/gimpconfigtypes.h b/libgimpconfig/gimpconfigtypes.h
index be36713935..0260477054 100644
--- a/libgimpconfig/gimpconfigtypes.h
+++ b/libgimpconfig/gimpconfigtypes.h
@@ -19,9 +19,7 @@
  * <https://www.gnu.org/licenses/>.
  */
 
-#ifndef __GIMP_CONFIG_TYPES_H__
-#define __GIMP_CONFIG_TYPES_H__
-
+#pragma once
 
 #include <libgimpbase/gimpbasetypes.h>
 
@@ -34,6 +32,3 @@ typedef struct _GScanner          GimpScanner;
 typedef struct _GimpColorConfig   GimpColorConfig;
 
 #include <libgimpconfig/gimpconfigenums.h>
-
-
-#endif  /* __GIMP_CONFIG_TYPES_H__ */
diff --git a/libgimpconfig/gimpconfigwriter.h b/libgimpconfig/gimpconfigwriter.h
index 5e60fa3427..4ff27830a0 100644
--- a/libgimpconfig/gimpconfigwriter.h
+++ b/libgimpconfig/gimpconfigwriter.h
@@ -19,13 +19,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_CONFIG_WRITER_H__
-#define __GIMP_CONFIG_WRITER_H__
-
 
 /**
  * GIMP_TYPE_CONFIG_WRITER:
@@ -81,6 +80,3 @@ void               gimp_config_writer_close        (GimpConfigWriter  *writer);
 gboolean           gimp_config_writer_finish       (GimpConfigWriter  *writer,
                                                     const gchar       *footer,
                                                     GError           **error);
-
-
-#endif /* __GIMP_CONFIG_WRITER_H__ */
diff --git a/libgimpconfig/gimpscanner.h b/libgimpconfig/gimpscanner.h
index e690c9be2e..753b789f44 100644
--- a/libgimpconfig/gimpscanner.h
+++ b/libgimpconfig/gimpscanner.h
@@ -20,13 +20,12 @@
  * <https://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if !defined (__GIMP_CONFIG_H_INSIDE__) && !defined (GIMP_CONFIG_COMPILATION)
 #error "Only <libgimpconfig/gimpconfig.h> can be included directly."
 #endif
 
-#ifndef __GIMP_SCANNER_H__
-#define __GIMP_SCANNER_H__
-
 
 /**
  * GIMP_TYPE_SCANNER:
@@ -75,6 +74,3 @@ gboolean      gimp_scanner_parse_color              (GimpScanner   *scanner,
                                                      GeglColor    **color);
 gboolean      gimp_scanner_parse_matrix2            (GimpScanner   *scanner,
                                                      GimpMatrix2   *dest);
-
-
-#endif /* __GIMP_SCANNER_H__ */