diff --git a/cty/marks_test.go b/cty/marks_test.go
index 848b638..ec4196c 100644
--- a/cty/marks_test.go
+++ b/cty/marks_test.go
@@ -489,3 +489,21 @@ func TestPathValueMarks(t *testing.T) {
 		})
 	}
 }
+
+func TestReapplyMarks(t *testing.T) {
+	// Re-applying the same marks to an object value should not change the result.
+	obj := ObjectVal(map[string]Value{
+		"nested": ObjectVal(map[string]Value{
+			"attr": StringVal("not directly marked"),
+		}),
+	})
+
+	pvm := []PathValueMarks{{Path: GetAttrPath("nested"), Marks: NewValueMarks("mark")}}
+
+	first := obj.MarkWithPaths(pvm)
+	second := first.MarkWithPaths(pvm)
+
+	if !first.RawEquals(second) {
+		t.Fatalf("Value changed re-applying marks\n1st: %#v\n2nd: %#v\n", first, second)
+	}
+}
diff --git a/cty/walk.go b/cty/walk.go
index 87ba32e..a18af04 100644
--- a/cty/walk.go
+++ b/cty/walk.go
@@ -213,7 +213,7 @@ func transform(path Path, val Value, t Transformer) (Value, error) {
 			atys := ty.AttributeTypes()
 			newAVs := make(map[string]Value)
 			for name := range atys {
-				av := val.GetAttr(name)
+				av := rawVal.GetAttr(name)
 				path := append(path, GetAttrStep{
 					Name: name,
 				})
diff --git a/cty/walk_test.go b/cty/walk_test.go
index 80a672e..98d56f1 100644
--- a/cty/walk_test.go
+++ b/cty/walk_test.go
@@ -261,3 +261,26 @@ func TestTransform(t *testing.T) {
 		t.Fatalf("wrong value\n got: %#v\nwant: %#v", gotVal, wantVal)
 	}
 }
+
+func TestTransformMarked(t *testing.T) {
+	val := ObjectVal(map[string]Value{
+		"list": ListVal([]Value{True, True, False}).Mark("mark"),
+		"set":  SetVal([]Value{True, False}).Mark("mark"),
+		"map":  MapVal(map[string]Value{"a": True, "b": False}).Mark("mark"),
+		"object": ObjectVal(map[string]Value{
+			"a": True,
+			"b": ListVal([]Value{False, False, False}),
+		}).Mark("mark"),
+	})
+
+	// This noop transform should not change any values or marks.
+	gotVal, err := Transform(val, func(p Path, v Value) (Value, error) {
+		return v, nil
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+	if !gotVal.RawEquals(val) {
+		t.Fatalf("wrong value\n got: %#v\nwant: %#v", gotVal, val)
+	}
+}