diff --git a/marshal.c b/marshal.c
index af952048af..cdf25df5aa 100644
--- a/marshal.c
+++ b/marshal.c
@@ -1803,6 +1803,20 @@ r_object0(struct load_arg *arg, bool partial, int *ivp, VALUE extmod)
     return r_object_for(arg, partial, ivp, extmod, type);
 }
 
+static int
+r_move_ivar(st_data_t k, st_data_t v, st_data_t d)
+{
+    ID key = (ID)k;
+    VALUE value = (VALUE)v;
+    VALUE dest = (VALUE)d;
+
+    if (rb_is_instance_id(key)) {
+        rb_ivar_set(dest, key, value);
+        return ST_DELETE;
+    }
+    return ST_CONTINUE;
+}
+
 static VALUE
 r_object_for(struct load_arg *arg, bool partial, int *ivp, VALUE extmod, int type)
 {
@@ -1826,7 +1840,6 @@ r_object_for(struct load_arg *arg, bool partial, int *ivp, VALUE extmod, int typ
       case TYPE_IVAR:
         {
             int ivar = TRUE;
-
             v = r_object0(arg, true, &ivar, extmod);
             if (ivar) r_ivar(v, NULL, arg);
             v = r_leave(v, arg, partial);
@@ -2020,7 +2033,10 @@ r_object_for(struct load_arg *arg, bool partial, int *ivp, VALUE extmod, int typ
                 }
                 rb_str_set_len(str, dst - ptr);
             }
-            v = r_entry0(rb_reg_new_str(str, options), idx, arg);
+            VALUE regexp = rb_reg_new_str(str, options);
+            rb_ivar_foreach(str, r_move_ivar, regexp);
+
+            v = r_entry0(regexp, idx, arg);
             v = r_leave(v, arg, partial);
         }
         break;
diff --git a/spec/ruby/core/marshal/shared/load.rb b/spec/ruby/core/marshal/shared/load.rb
index 8fdfedd746..1df2e8d4f1 100644
--- a/spec/ruby/core/marshal/shared/load.rb
+++ b/spec/ruby/core/marshal/shared/load.rb
@@ -740,6 +740,17 @@ describe :marshal_load, shared: true do
       new_obj_metaclass_ancestors[@num_self_class, 3].should ==
         [Meths, UserRegexp, Regexp]
     end
+
+    ruby_bug "#19439", ""..."3.3" do
+      it "restore the regexp instance variables" do
+        obj = Regexp.new("hello")
+        obj.instance_variable_set(:@regexp_ivar, [42])
+
+        new_obj = Marshal.send(@method, "\x04\bI/\nhello\x00\a:\x06EF:\x11@regexp_ivar[\x06i/")
+        new_obj.instance_variables.should == [:@regexp_ivar]
+        new_obj.instance_variable_get(:@regexp_ivar).should == [42]
+      end
+    end
   end
 
   describe "for a Float" do