diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-object.c b/jerry-core/ecma/builtin-objects/ecma-builtin-object.c
index e5297fc24..44f9bdef0 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-object.c
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-object.c
@@ -1014,7 +1014,7 @@ ecma_builtin_object_dispatch_routine (uint16_t builtin_routine_id, /**< built-in
 #if ENABLED (JERRY_ES2015)
     if (!ecma_is_value_object (arg1))
     {
-      return arg1;
+      return ecma_copy_value (arg1);
     }
 #endif /* ENABLED (JERRY_ES2015) */
 
diff --git a/tests/jerry/es2015/object-methods.js b/tests/jerry/es2015/object-methods.js
index 3b5cea5da..dca58a673 100644
--- a/tests/jerry/es2015/object-methods.js
+++ b/tests/jerry/es2015/object-methods.js
@@ -30,19 +30,31 @@ assert (d.enumerable === true);
 assert (d.configurable === false);
 
 assert (Object.seal(42) === 42);
+assert (Object.seal("a") === "a");
 assert (Object.seal(undefined) === undefined);
+assert (Object.seal() === undefined);
 
 assert (Object.isSealed(42) === true);
+assert (Object.isSealed("a") === true);
 assert (Object.isSealed(undefined) === true);
+assert (Object.isSealed() === true);
 
 assert (Object.freeze(42) === 42);
+assert (Object.freeze("a") === "a");
 assert (Object.freeze(undefined) === undefined);
+assert (Object.freeze() === undefined);
 
 assert (Object.isFrozen(42) === true);
+assert (Object.isFrozen("a") === true);
 assert (Object.isFrozen(undefined) === true);
+assert (Object.isFrozen() === true);
 
 assert (Object.preventExtensions(42) === 42);
+assert (Object.preventExtensions("a") === "a");
 assert (Object.preventExtensions(undefined) === undefined);
+assert (Object.preventExtensions() === undefined);
 
 assert (Object.isExtensible(42) === false);
+assert (Object.isExtensible("a") === false);
 assert (Object.isExtensible(undefined) === false);
+assert (Object.isExtensible() === false);