diff --git a/screen-write.c b/screen-write.c
index 923dac6e..6892d041 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -2110,7 +2110,7 @@ screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 
 	/*
 	 * Check if we need to combine characters. This could be zero width
-	 * (zet above), a modifier character (with an existing Unicode
+	 * (set above), a modifier character (with an existing Unicode
 	 * character) or a previous ZWJ.
 	 */
 	if (!zero_width) {
@@ -2122,6 +2122,10 @@ screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 			return (0);
 	}
 
+	/* Check if this combined character would be too long. */
+	if (last.data.size + ud->size > sizeof last.data.data)
+		return (0);
+
 	/* Combining; flush any pending output. */
 	screen_write_collect_flush(ctx, 0, __func__);
 
diff --git a/window-copy.c b/window-copy.c
index 6f233077..bc3713b0 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -2719,7 +2719,7 @@ static const struct {
 	},
 	{ .command = "next-prompt",
 	  .minargs = 0,
-	  .maxargs = 0,
+	  .maxargs = 1,
 	  .clear = WINDOW_COPY_CMD_CLEAR_ALWAYS,
 	  .f = window_copy_cmd_next_prompt
 	},
diff --git a/window.c b/window.c
index 84a32393..81d0f809 100644
--- a/window.c
+++ b/window.c
@@ -338,6 +338,7 @@ window_destroy(struct window *w)
 {
 	log_debug("window @%u destroyed (%d references)", w->id, w->references);
 
+	window_unzoom(w);
 	RB_REMOVE(windows, &windows, w);
 
 	if (w->layout_root != NULL)