diff --git a/compile.c b/compile.c
index 17974b26c0..18abaca22b 100644
--- a/compile.c
+++ b/compile.c
@@ -8773,7 +8773,15 @@ ibf_load_iseq_each(const struct ibf_load *load, rb_iseq_t *iseq, ibf_offset_t of
 		rb_raise(rb_eRuntimeError, "path object size mismatch");
 	    }
 	    path = rb_fstring(RARRAY_AREF(pathobj, 0));
-	    realpath = rb_fstring(RARRAY_AREF(pathobj, 1));
+	    realpath = RARRAY_AREF(pathobj, 1);
+	    if (!NIL_P(realpath)) {
+		if (!RB_TYPE_P(realpath, T_STRING)) {
+		    rb_raise(rb_eArgError, "unexpected realpath %"PRIxVALUE
+			     "(%x), path=%+"PRIsVALUE,
+			     realpath, TYPE(realpath), path);
+		}
+		realpath = rb_fstring(realpath);
+	    }
 	}
 	else {
 	    rb_raise(rb_eRuntimeError, "unexpected path object");
diff --git a/test/ruby/test_iseq.rb b/test/ruby/test_iseq.rb
index 4c811611ba..1a45778cc4 100644
--- a/test/ruby/test_iseq.rb
+++ b/test/ruby/test_iseq.rb
@@ -398,10 +398,9 @@ class TestISeq < Test::Unit::TestCase
 
   def test_to_binary_with_objects
     code = "[]"+100.times.map{|i|"<</#{i}/"}.join
-    bin = assert_nothing_raised {
-      RubyVM::InstructionSequence.compile(code).to_binary
-    }
-    # load_from_binary doesn't work now
-    assert_instance_of(String, bin)
+    iseq = RubyVM::InstructionSequence.compile(code)
+    bin = assert_nothing_raised {iseq.to_binary}
+    iseq2 = RubyVM::InstructionSequence.load_from_binary(bin)
+    assert_equal(iseq2.to_a, iseq.to_a)
   end
 end