diff --git a/src/frontend/inp.c b/src/frontend/inp.c
index 971696e95..310b71b48 100644
--- a/src/frontend/inp.c
+++ b/src/frontend/inp.c
@@ -775,6 +775,17 @@ inp_spsource(FILE *fp, bool comfile, char *filename, bool intfile)
                     commands = FALSE;
                 else
                     fprintf(cp_err, "Warning: misplaced .endc card\n");
+            } else if (!commands && ciprefix(".hb", dd->line) &&
+                       (dd->line[3] == '\0' || isspace_c(dd->line[3]))) {
+                /* Enhancement-162: a top-level `.hb ...` card is run after the
+                 * circuit is parsed as an `hb ...` command (Enhancement-134
+                 * harmonic balance), mirroring the `.sweep` handling above -- drop
+                 * the leading '.' and add it to the post-parse control list. The
+                 * boundary check keeps `.hb` from swallowing any future `.hb*`
+                 * card. */
+                controls = wl_cons(copy(skip_ws(dd->line) + 1), controls);
+                ld->nextcard = dd->nextcard;
+                line_free(dd, FALSE);
             } else if (commands || prefix("*#", dd->line)) {
                 s = dd->line;