diff --git a/src/vte.c b/src/vte.c
index ca7fe09..cba8605 100644
--- a/src/vte.c
+++ b/src/vte.c
@@ -3106,6 +3106,8 @@ _vte_terminal_insert_char(VteTerminal *terminal, gunichar c,
 		columns = _vte_iso2022_unichar_width(terminal->pvt->iso2022, c);
 	}
 
+	if (G_UNLIKELY (g_unichar_type(c) == G_UNICODE_SPACING_MARK))
+		columns = 0;
 
 	/* If we're autowrapping here, do it. */
 	col = screen->cursor_current.col;
