diff --git a/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c b/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c
index 5e25789c71..9d1ad207e1 100644
--- a/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c
+++ b/jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c
@@ -125,7 +125,7 @@ ecma_builtin_array_prototype_object_to_string (ecma_value_t this_arg) /**< this
  *         Returned value must be freed with ecma_free_value.
  */
 static ecma_value_t
-ecma_builtin_array_prototype_object_to_locale_string (const ecma_value_t this_arg) /**< this argument */
+ecma_builtin_array_prototype_object_to_locale_string (ecma_value_t this_arg) /**< this argument */
 {
   ecma_value_t ret_value = ECMA_VALUE_EMPTY;
 
@@ -331,8 +331,8 @@ ecma_op_array_get_to_string_at_index (ecma_object_t *obj_p, /**< this object */
  *         Returned value must be freed with ecma_free_value.
  */
 static ecma_value_t
-ecma_builtin_array_prototype_join (const ecma_value_t this_arg, /**< this argument */
-                                   const ecma_value_t separator_arg) /**< separator argument */
+ecma_builtin_array_prototype_join (ecma_value_t this_arg, /**< this argument */
+                                   ecma_value_t separator_arg) /**< separator argument */
 {
   ecma_value_t ret_value = ECMA_VALUE_EMPTY;
 
diff --git a/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c b/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c
index fbc467648d..69fa50fb6f 100644
--- a/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c
+++ b/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c
@@ -837,8 +837,8 @@ ecma_op_typedarray_get_separator_string (ecma_value_t separator) /**< possible s
  *         Returned value must be freed with ecma_free_value.
  */
 static ecma_value_t
-ecma_builtin_typedarray_prototype_join (const ecma_value_t this_arg, /**< this argument */
-                                        const ecma_value_t separator_arg) /**< separator argument */
+ecma_builtin_typedarray_prototype_join (ecma_value_t this_arg, /**< this argument */
+                                        ecma_value_t separator_arg) /**< separator argument */
 {
   /* 1. */
   ecma_value_t obj_value = ecma_op_to_object (this_arg);
diff --git a/jerry-core/lit/lit-strings.h b/jerry-core/lit/lit-strings.h
index c83bf82c3b..208108bde8 100644
--- a/jerry-core/lit/lit-strings.h
+++ b/jerry-core/lit/lit-strings.h
@@ -108,7 +108,7 @@ lit_string_hash_t lit_utf8_string_hash_combine (lit_string_hash_t hash_basis, co
 /* code unit access */
 ecma_char_t lit_utf8_string_code_unit_at (const lit_utf8_byte_t *utf8_buf_p, lit_utf8_size_t utf8_buf_size,
                                           ecma_length_t code_unit_offset);
-lit_utf8_size_t lit_get_unicode_char_size_by_utf8_first_byte (lit_utf8_byte_t first_byte);
+lit_utf8_size_t lit_get_unicode_char_size_by_utf8_first_byte (const lit_utf8_byte_t first_byte);
 
 /* conversion */
 lit_utf8_size_t lit_code_unit_to_utf8 (ecma_char_t code_unit, lit_utf8_byte_t *buf_p);