diff --git a/compile.c b/compile.c
index 9230935819..a6ce631513 100644
--- a/compile.c
+++ b/compile.c
@@ -5950,6 +5950,7 @@ iseq_build_from_ary_body(rb_iseq_t *iseq, LINK_ANCHOR *anchor,
 			}
 			break;
 		      case TS_FUNCPTR:
+			if (!RTEST(op)) rb_raise(rb_eArgError, "cannot load funcptr");
 			argv[j] = op;
 			break;
 		      default:
diff --git a/iseq.c b/iseq.c
index de304906fe..297299e00a 100644
--- a/iseq.c
+++ b/iseq.c
@@ -1973,6 +1973,9 @@ iseq_data_to_ary(rb_iseq_t *iseq)
 		    rb_ary_push(ary, val);
 		}
 		break;
+	      case TS_FUNCPTR:
+		rb_ary_push(ary, Qnil);
+		break;
 	      default:
 		rb_bug("unknown operand: %c", insn_op_type(insn, j));
 	    }