diff --git a/src/server.c b/src/server.c
index 18000f2..0f6b083 100644
--- a/src/server.c
+++ b/src/server.c
@@ -58,6 +58,7 @@ void server_init_atoms ()
 	server.atom._NET_WM_STATE_MAXIMIZED_VERT = XInternAtom (server.dsp, "_NET_WM_STATE_MAXIMIZED_VERT", False);
 	server.atom._NET_WM_STATE_MAXIMIZED_HORZ = XInternAtom (server.dsp, "_NET_WM_STATE_MAXIMIZED_HORZ", False);
 	server.atom._NET_WM_STATE_SHADED = XInternAtom (server.dsp, "_NET_WM_STATE_SHADED", False);
+	server.atom._NET_WM_STATE_HIDDEN = XInternAtom (server.dsp, "_NET_WM_STATE_HIDDEN", False);
 	server.atom._NET_WM_STATE_BELOW = XInternAtom (server.dsp, "_NET_WM_STATE_BELOW", False);
 	server.atom._NET_WM_STATE_ABOVE = XInternAtom (server.dsp, "_NET_WM_STATE_ABOVE", False);
 	server.atom._NET_WM_STATE_MODAL = XInternAtom (server.dsp, "_NET_WM_STATE_MODAL", False);
diff --git a/src/server.h b/src/server.h
index 3da2f04..517cd84 100644
--- a/src/server.h
+++ b/src/server.h
@@ -40,6 +40,7 @@ typedef struct Global_atom
 	Atom _NET_WM_STATE_MAXIMIZED_VERT;
 	Atom _NET_WM_STATE_MAXIMIZED_HORZ;
 	Atom _NET_WM_STATE_SHADED;
+	Atom _NET_WM_STATE_HIDDEN;
 	Atom _NET_WM_STATE_BELOW;
 	Atom _NET_WM_STATE_ABOVE;
 	Atom _NET_WM_STATE_MODAL;
diff --git a/src/util/window.c b/src/util/window.c
index 285d525..06ab093 100644
--- a/src/util/window.c
+++ b/src/util/window.c
@@ -146,20 +146,18 @@ int window_get_monitor (Window win)
 
 int window_is_iconified (Window win)
 {
-	if (IconicState == get_property32(win, server.atom.WM_STATE, server.atom.WM_STATE)) {
-		// openbox sets on shaded windows the IconicState, however we do not consider these windows iconified
-		Atom *at;
-		int count, i;
-		at = server_get_property (win, server.atom._NET_WM_STATE, XA_ATOM, &count);
-		for (i = 0; i < count; i++) {
-			if (at[i] == server.atom._NET_WM_STATE_SHADED) {
-				XFree(at);
-				return 0;
-			}
+	// EWMH specification : minimization of windows use _NET_WM_STATE_HIDDEN.
+	// WM_STATE is not accurate for shaded window and in multi_desktop mode.
+	Atom *at;
+	int count, i;
+	at = server_get_property (win, server.atom._NET_WM_STATE, XA_ATOM, &count);
+	for (i = 0; i < count; i++) {
+		if (at[i] == server.atom._NET_WM_STATE_HIDDEN) {
+			XFree(at);
+			return 1;
 		}
-		XFree(at);
-		return 1;
 	}
+	XFree(at);
 	return 0;
 }