diff --git a/bootstraptest/test_ractor.rb b/bootstraptest/test_ractor.rb
index 01d02dce77..4da348df67 100644
--- a/bootstraptest/test_ractor.rb
+++ b/bootstraptest/test_ractor.rb
@@ -187,6 +187,28 @@ assert_equal '[:ok, :ok, :ok]', %q{
   }.map(&:take)
 }
 
+# Ractor.make_shareable issue for locals in proc [Bug #18023]
+assert_equal '[:a, :b, :c, :d, :e]', %q{
+  v1, v2, v3, v4, v5 = :a, :b, :c, :d, :e
+  closure = Proc.new { [v1, v2, v3, v4, v5] }
+
+  Ractor.make_shareable(closure).call
+}
+
+# Ractor.make_shareable issue for locals in proc [Bug #18023]
+assert_equal '[:a, :b, :c, :d, :e, :f, :g]', %q{
+  a = :a
+  closure = -> {
+    b, c, d = :b, :c, :d
+    -> {
+      e, f, g = :e, :f, :g
+      -> { [a, b, c, d, e, f, g] }
+    }.call
+  }.call
+
+  Ractor.make_shareable(closure).call
+}
+
 ###
 ###
 # Ractor still has several memory corruption so skip huge number of tests
diff --git a/vm.c b/vm.c
index 5a1756e33a..d5e984ce61 100644
--- a/vm.c
+++ b/vm.c
@@ -1006,7 +1006,7 @@ env_copy(const VALUE *src_ep, VALUE read_only_variables)
     volatile VALUE prev_env = Qnil;
 
     if (read_only_variables) {
-        for (int i=0; i<RARRAY_LENINT(read_only_variables); i++) {
+        for (int i=RARRAY_LENINT(read_only_variables)-1; i>=0; i--) {
             ID id = SYM2ID(rb_str_intern(RARRAY_AREF(read_only_variables, i)));
 
             for (unsigned int j=0; j<src_env->iseq->body->local_table_size; j++) {