diff --git a/README.md b/README.md
index 9942e84..781d7a4 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,11 @@ Some elements that proved to be the wrong direction for xoat have been removed.
 	* Snapshot allows the freedom to mess windows up then quicky revert to a known state.
 * Some EWMH desktop atoms have been dumped as surplus to requirements.
 
-
+### config.h
+
+All customization happens in config.h. See in-line comments there.
+
+**Note**: config.h is tracked! Use a local git branch to protect any customization.
 
 
 
diff --git a/config.h b/config.h
index 98111ee..c457281 100644
--- a/config.h
+++ b/config.h
@@ -103,6 +103,7 @@ binding keys[] = {
 	{ .mod = Mod4Mask, .key = XK_r, .act = ACTION_ROLLBACK },
 
 	// Find or start apps by WM_CLASS (lower case match).
+	// Only works for apps that use some form of their binary name as their class...
 	{ .mod = AnyModifier, .key = XK_F1, .act = ACTION_FIND_OR_START, .data = "urxvt"    },
 	{ .mod = AnyModifier, .key = XK_F2, .act = ACTION_FIND_OR_START, .data = "chromium" },
 	{ .mod = AnyModifier, .key = XK_F3, .act = ACTION_FIND_OR_START, .data = "pcmanfm"  },
diff --git a/xoat.c b/xoat.c
index f325a83..bd5da58 100644
--- a/xoat.c
+++ b/xoat.c
@@ -513,8 +513,9 @@ void action_find_or_start(void *data, int num, client *cli)
 {
 	int i; client *c; char *class = data;
 
-	for_windows(i, c) if (c->manage && !strcasecmp(c->class, class))
-		{ client_activate(c); return; }
+	for_windows(i, c)
+		if (c->visible && c->manage && c->class && !strcasecmp(c->class, class))
+			{ client_activate(c); return; }
 
 	exec_cmd(class);
 }
@@ -579,7 +580,7 @@ void action_rollback(void *data, int num, client *cli)
 	for (i = snapshot.depth-1; i > -1; i--)
 	{
 		if ((s = snapshot.clients[i]) && (c = window_build_client(s->window))
-			&& !strcmp(s->class, c->class) && c->visible && c->manage)
+			&& c->class && !strcmp(s->class, c->class) && c->visible && c->manage)
 		{
 			client_place_spot(c, s->spot, s->monitor, 1);
 			client_raise_family(c);