diff --git a/src/client.h b/src/client.h
index 41e08d7c050ffddb0aaeeb3a50243c17e58c4308..41f083c3b639d6881663040b103ae4d4a24960a8 100644
--- a/src/client.h
+++ b/src/client.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __CLIENT_H__
-#define __CLIENT_H__
+#ifndef INC_CLIENT_H__
+#define INC_CLIENT_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -260,4 +260,4 @@ Client *clientGetLeader(Client *);
 char *clientGetStartupId(Client *);
 #endif
 
-#endif /* __CLIENT_H__ */
+#endif /* INC_CLIENT_H__ */
diff --git a/src/debug.h b/src/debug.h
index cd2558ad43f331063b10e8530a784dd170fd5c58..85cccad66cc2648a0227b536957528b0d17a1d8f 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -15,8 +15,8 @@
 
  */
 
-#ifndef __DEBUG_H__
-#define __DEBUG_H__
+#ifndef INC_DEBUG_H__
+#define INC_DEBUG_H__
 
 #if defined(DEBUG) && DEBUG
 #include <stdio.h>
@@ -25,4 +25,4 @@
 #define DBG(fmt, args...) do {} while(0)
 #endif
 
-#endif /* __DEBUG_H__ */
+#endif /* INC_DEBUG_H__ */
diff --git a/src/events.h b/src/events.h
index 704c15ddc8eff53fd6ce9b35e55798ffbc07ff72..034883cc75ca2b69a96bcc2de1783f84fb234cd8 100644
--- a/src/events.h
+++ b/src/events.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __EVENTS_H__
-#define __EVENTS_H__
+#ifndef INC_EVENTS_H__
+#define INC_EVENTS_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -36,4 +36,4 @@ void handleEvent(XEvent *);
 GtkToXEventFilterStatus xfwm4_event_filter(XEvent * xevent, gpointer data);
 void initGtkCallbacks(void);
 
-#endif /* __EVENTS_H__ */
+#endif /* INC_EVENTS_H__ */
diff --git a/src/frame.h b/src/frame.h
index d48d4c76379d6fe3dbe5afec018cfae5332604d0..6c43bb5549309591760572daf1eaff9436b1daa8 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __FRAME_H__
-#define __FRAME_H__
+#ifndef INC_FRAME_H__
+#define INC_FRAME_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -37,4 +37,4 @@ inline int frameWidth(Client *);
 inline int frameHeight(Client *);
 void frameDraw(Client *, gboolean, gboolean);
 
-#endif /* __FRAME_H__ */
+#endif /* INC_FRAME_H__ */
diff --git a/src/hints.h b/src/hints.h
index cb7ef4c17eb91e96ff168c4d0c9691d5dce53365..922d3ee6ea3adad3ab93408c432c8fb94dde1ff4 100644
--- a/src/hints.h
+++ b/src/hints.h
@@ -19,8 +19,8 @@
 
  */
 
-#ifndef __HINTS_H__
-#define __HINTS_H__
+#ifndef INC_HINTS_H__
+#define INC_HINTS_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -209,4 +209,4 @@ gboolean getWindowStartupId(Display *, Window, char **);
 #define setNetHint setGnomeHint
 #define getNetHint getGnomeHint
 
-#endif /* __HINTS_H__ */
+#endif /* INC_HINTS_H__ */
diff --git a/src/keyboard.h b/src/keyboard.h
index 5e47195ef6466d3879150fc201354f84d9d7c22c..8e380f587cb104824a6b81b833a779d42ef7c27a 100644
--- a/src/keyboard.h
+++ b/src/keyboard.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __KEYBOARD_H
-#define __KEYBOARD_H
+#ifndef INC_KEYBOARD_H
+#define INC_KEYBOARD_H
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -50,4 +50,4 @@ void grabKey(Display *, MyKey *, Window);
 void ungrabKeys(Display *, Window);
 void initModifiers(Display *);
 
-#endif /* __KEYBOARD_H */
+#endif /* INC_KEYBOARD_H */
diff --git a/src/main.h b/src/main.h
index ba538fab065853151d7c897aaca2bc49f0b22abc..900efe14e85925fb122b64871866c6bf08138e8d 100644
--- a/src/main.h
+++ b/src/main.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __MAIN_H__
-#define __MAIN_H__
+#ifndef INC_MAIN_H__
+#define INC_MAIN_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -72,4 +72,4 @@ extern Cursor resize_cursor[7], move_cursor, busy_cursor, root_cursor;
  *
  */
 
-#endif /* __MAIN_H__ */
+#endif /* INC_MAIN_H__ */
diff --git a/src/menu.h b/src/menu.h
index a36f19a04eef39be25681a32beb74cb7736d2b8e..eeb19da970379699e475c49362d4f49d296f057b 100644
--- a/src/menu.h
+++ b/src/menu.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __MENU_H__
-#define __MENU_H__
+#ifndef INC_MENU_H__
+#define INC_MENU_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -90,4 +90,4 @@ gboolean menu_check_and_close(void);
 gboolean menu_popup(Menu * menu, int root_x, int root_y, int button, guint32 timestamp);
 void menu_free(Menu * menu);
 
-#endif /* __MENU_H__ */
+#endif /* INC_MENU_H__ */
diff --git a/src/misc.h b/src/misc.h
index bbaab1da96baf5afb93d9f8174b48acc70fdb248..b0fef92c1b6d2a4e6164a621dc7b8ea7d6be0b41 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __MISC_H__
-#define __MISC_H__
+#ifndef INC_MISC_H__
+#define INC_MISC_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -35,4 +35,4 @@ void sendClientMessage(Window, Atom, long, int);
 Window setTmpEventWin(long);
 void removeTmpEventWin(Window);
 
-#endif /* __MISC_H__ */
+#endif /* INC_MISC_H__ */
diff --git a/src/mywindow.h b/src/mywindow.h
index 8b73ab3b7fc70be2b0589da2da82c3ab8109d95c..4a677995f21552848f623181a2bf0428cf50c801 100644
--- a/src/mywindow.h
+++ b/src/mywindow.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __MYWINDOW_H__
-#define __MYWINDOW_H__
+#ifndef INC_MYWINDOW_H__
+#define INC_MYWINDOW_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -45,4 +45,4 @@ void myWindowDelete(myWindow *);
 void myWindowShow(myWindow *, int, int, int, int, gboolean);
 void myWindowHide(myWindow *);
 
-#endif /* __MYWINDOW_H__ */
+#endif /* INC_MYWINDOW_H__ */
diff --git a/src/parserc.h b/src/parserc.h
index e189f06c171a2283043d7ed7f2ea546ec33dc449..fd02198cc824a09b1613fe36fcb89fbb424c2809 100644
--- a/src/parserc.h
+++ b/src/parserc.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __PARSERC_H__
-#define __PARSERC_H__
+#ifndef INC_PARSERC_H__
+#define INC_PARSERC_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -37,4 +37,4 @@ gboolean setIntValueFromInt(const gchar *, int, Settings rc[]);
 gchar *getThemeDir(const gchar *);
 void freeRc(Settings rc[]);
 
-#endif /* __PARSERC_H__ */
+#endif /* INC_PARSERC_H__ */
diff --git a/src/pixmap.h b/src/pixmap.h
index 6ecc6f7fdd4c8cfed3690f8f4b62bdf3a41a5bb2..0476186c8fce38d8e990d0f64564476c0b8ebfbd 100644
--- a/src/pixmap.h
+++ b/src/pixmap.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __PIXMAP_H__
-#define __PIXMAP_H__
+#ifndef INC_PIXMAP_H__
+#define INC_PIXMAP_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -40,4 +40,4 @@ void createPixmap(Display *, MyPixmap *, gint, gint);
 void initPixmap(MyPixmap *);
 void freePixmap(Display *, MyPixmap *);
 
-#endif /* __PIXMAP_H__ */
+#endif /* INC_PIXMAP_H__ */
diff --git a/src/session.h b/src/session.h
index 77b83477185859914df0f721a7f19a65fd295aa3..cd6a2b931cd2679b35a1e66197b9fa8a75c67fe3 100644
--- a/src/session.h
+++ b/src/session.h
@@ -16,8 +16,8 @@
 
  */
 
-#ifndef __SESSION_H__
-#define __SESSION_H__
+#ifndef INC_SESSION_H__
+#define INC_SESSION_H__
 
 #include <glib.h>
 #include "client.h"
@@ -43,4 +43,4 @@ void sessionFreeWindowStates(void);
 */
 gboolean sessionMatchWinToSM(Client *);
 
-#endif /* __CLIENT_H__ */
+#endif /* INC_CLIENT_H__ */
diff --git a/src/settings.h b/src/settings.h
index 28df9a62f8e6617766854d11d2fc098e9f278810..84a54b593dd17e5e88e149ee15c105942cdcba86 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __SETTINGS_H__
-#define __SETTINGS_H__
+#ifndef INC_SETTINGS_H__
+#define INC_SETTINGS_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -177,4 +177,4 @@ void unloadSettings(void);
 gboolean reloadSettings(int);
 gboolean initSettings(void);
 
-#endif /* __SETTINGS_H__ */
+#endif /* INC_SETTINGS_H__ */
diff --git a/src/spinning_cursor.h b/src/spinning_cursor.h
index 465dc9ee944a47cd21ece654a370a85ef88f61c9..07f93f83e14d97f243ec77e4a8eb47ac1b7d12b9 100644
--- a/src/spinning_cursor.h
+++ b/src/spinning_cursor.h
@@ -22,11 +22,11 @@
 #  include "config.h"
 #endif
 
-#ifndef __SPINNING_CURSOR_H__
-#define __SPINNING_CURSOR_H__
+#ifndef INC_SPINNING_CURSOR_H__
+#define INC_SPINNING_CURSOR_H__
 
 #include <X11/Xlib.h>
 
 Cursor cursorCreateSpinning(Display * dpy, Window window);
 
-#endif /* __SPINNING_CURSOR_H__ */
+#endif /* INC_SPINNING_CURSOR_H__ */
diff --git a/src/startup_notification.h b/src/startup_notification.h
index 9b7a03e26558b86a33a81127f947af3bdef42600..ac4cc838694e9296e2ef94c855b2ddb55416c9c3 100644
--- a/src/startup_notification.h
+++ b/src/startup_notification.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __STARTUP_NOTIFICATION_H__
-#define __STARTUP_NOTIFICATION_H__
+#ifndef INC_STARTUP_NOTIFICATION_H__
+#define INC_STARTUP_NOTIFICATION_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -45,4 +45,4 @@ void sn_process_event(XEvent * event);
 #define sn_process_event(e) ;
 
 #endif /* HAVE_STARTUP_NOTIFICATION */
-#endif /* __STARTUP_NOTIFICATION_H__ */
+#endif /* INC_STARTUP_NOTIFICATION_H__ */
diff --git a/src/tabwin.h b/src/tabwin.h
index d875dc1c336f03c25b60190dbd8d1ff6576a62c0..cc72160e1b30a5d6316835cd8473f49329082299 100644
--- a/src/tabwin.h
+++ b/src/tabwin.h
@@ -21,8 +21,8 @@
 #  include "config.h"
 #endif
 
-#ifndef __TABWIN_H__
-#define __TABWIN_H__
+#ifndef INC_TABWIN_H__
+#define INC_TABWIN_H__
 
 #include <glib.h>
 #include <gdk/gdk.h>
@@ -41,4 +41,4 @@ Tabwin *tabwinCreate(gchar * label);
 void tabwinSetLabel(Tabwin * tabwin, gchar * label);
 void tabwinDestroy(Tabwin * tabwin);
 
-#endif /* __TABWIN_H__ */
+#endif /* INC_TABWIN_H__ */
diff --git a/src/workspaces.h b/src/workspaces.h
index 0b00b8ca60433da070fbf1abbc9c57f736bee0f1..bfb987a196d6214ff0a557f35b23118bf88d9bea 100644
--- a/src/workspaces.h
+++ b/src/workspaces.h
@@ -18,8 +18,8 @@
 
  */
 
-#ifndef __WORKSPACES_H__
-#define __WORKSPACES_H__
+#ifndef INC_WORKSPACES_H__
+#define INC_WORKSPACES_H__
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -34,4 +34,4 @@ void workspaceSwitch(int, Client *);
 void workspaceSetCount(int);
 void workspaceUpdateArea(CARD32 *, CARD32 *);
 
-#endif /* __WORKSPACES_H__ */
+#endif /* INC_WORKSPACES_H__ */