diff --git a/jerry-core/parser/collections/array-list.cpp b/jerry-core/parser/collections/array-list.cpp
index 4603fbf69..500bc3a6b 100644
--- a/jerry-core/parser/collections/array-list.cpp
+++ b/jerry-core/parser/collections/array-list.cpp
@@ -17,11 +17,8 @@
 #include "mem-heap.h"
 #include "jrt-libc-includes.h"
 
-#define ARRAY_LIST_MAGIC 0x39
-
 typedef struct
 {
-  uint8_t magic;
   uint8_t element_size;
   size_t len;
   size_t size;
@@ -33,7 +30,6 @@ extract_header (array_list al)
 {
   JERRY_ASSERT (al != null_list);
   array_list_header *header = (array_list_header *) al;
-  JERRY_ASSERT (header->magic == ARRAY_LIST_MAGIC);
   return header;
 }
 
@@ -119,7 +115,6 @@ array_list_init (uint8_t element_size)
   size_t size = mem_heap_recommend_allocation_size (sizeof (array_list_header));
   array_list_header *header = (array_list_header *) mem_heap_alloc_block (size, MEM_HEAP_ALLOC_SHORT_TERM);
   memset (header, 0, size);
-  header->magic = ARRAY_LIST_MAGIC;
   header->element_size = element_size;
   header->len = 0;
   header->size = size;
diff --git a/jerry-core/parser/collections/hash-table.cpp b/jerry-core/parser/collections/hash-table.cpp
index 28544f13c..61f90292e 100644
--- a/jerry-core/parser/collections/hash-table.cpp
+++ b/jerry-core/parser/collections/hash-table.cpp
@@ -18,14 +18,11 @@
 #include "mem-heap.h"
 #include "jrt-libc-includes.h"
 
-#define HASH_MAP_MAGIC 0x67
-
 typedef struct
 {
   uint16_t (*hash) (void *);
   array_list *data;
   uint16_t size;
-  uint8_t magic;
   uint8_t key_size;
   uint8_t value_size;
   mem_heap_alloc_term_t alloc_term;
@@ -37,7 +34,6 @@ extract_header (hash_table ht)
 {
   JERRY_ASSERT (ht != null_hash);
   hash_table_int *hti = (hash_table_int *) ht;
-  JERRY_ASSERT (hti->magic == HASH_MAP_MAGIC);
   return hti;
 }
 
@@ -107,7 +103,6 @@ hash_table_init (uint8_t key_size, uint8_t value_size, uint16_t size,
 {
   hash_table_int *res = (hash_table_int *) mem_heap_alloc_block (sizeof (hash_table_int), alloc_term);
   memset (res, 0, sizeof (hash_table_int));
-  res->magic = HASH_MAP_MAGIC;
   res->key_size = key_size;
   res->value_size = value_size;
   res->size = size;
diff --git a/jerry-core/parser/collections/linked-list.cpp b/jerry-core/parser/collections/linked-list.cpp
index de0dccd12..96caef1c6 100644
--- a/jerry-core/parser/collections/linked-list.cpp
+++ b/jerry-core/parser/collections/linked-list.cpp
@@ -19,15 +19,10 @@
 #include "mem-heap.h"
 #include "lp-string.h"
 
-#define LINKED_LIST_MAGIC 0x42
-
 typedef struct linked_list_header
 {
   struct linked_list_header *next;
-  struct linked_list_header *prev;
-  uint16_t block_size;
   uint16_t element_size;
-  uint8_t magic;
 }
 linked_list_header;
 
@@ -35,13 +30,17 @@ linked_list_header;
 do { \
   linked_list_header *header = (linked_list_header *) list; \
   JERRY_ASSERT (header); \
-  JERRY_ASSERT (header->magic == LINKED_LIST_MAGIC); \
 } while (0);
 
+static size_t linked_list_block_size (uint16_t element_size)
+{
+  return mem_heap_recommend_allocation_size (sizeof (linked_list_header) + element_size) - sizeof (linked_list_header);
+}
+
 linked_list
 linked_list_init (uint16_t element_size)
 {
-  size_t size = mem_heap_recommend_allocation_size (element_size);
+  size_t size = sizeof (linked_list_header) + linked_list_block_size (element_size);
   linked_list list = (linked_list) mem_heap_alloc_block (size, MEM_HEAP_ALLOC_SHORT_TERM);
   if (list == null_list)
   {
@@ -50,10 +49,8 @@ linked_list_init (uint16_t element_size)
   }
   memset (list, 0, size);
   linked_list_header* header = (linked_list_header *) list;
-  header->magic = LINKED_LIST_MAGIC;
-  header->prev = header->next = null_list;
+  header->next = null_list;
   header->element_size = element_size;
-  header->block_size = (uint8_t) (size - sizeof (linked_list_header));
   return list;
 }
 
@@ -70,17 +67,18 @@ linked_list_free (linked_list list)
 }
 
 void *
-linked_list_element (linked_list list, uint16_t element_num)
+linked_list_element (linked_list list, size_t element_num)
 {
   ASSERT_LIST (list);
   linked_list_header *header = (linked_list_header *) list;
+  size_t block_size = linked_list_block_size (header->element_size);
   linked_list raw = list + sizeof (linked_list_header);
-  if (header->block_size < header->element_size * (element_num + 1))
+  if (block_size < header->element_size * (element_num + 1))
   {
     if (header->next)
     {
       return linked_list_element ((linked_list) header->next,
-                                  (uint16_t) (element_num - (header->block_size / header->element_size)));
+                                  element_num - (block_size / header->element_size));
     }
     else
     {
@@ -92,20 +90,20 @@ linked_list_element (linked_list list, uint16_t element_num)
 }
 
 void
-linked_list_set_element (linked_list list, uint16_t element_num, void *element)
+linked_list_set_element (linked_list list, size_t element_num, void *element)
 {
   ASSERT_LIST (list);
   linked_list_header *header = (linked_list_header *) list;
+  size_t block_size = linked_list_block_size (header->element_size);
   uint8_t *raw = (uint8_t *) (header + 1);
-  if (header->block_size < header->element_size * (element_num + 1))
+  if (block_size < header->element_size * (element_num + 1))
   {
     if (header->next == null_list)
     {
       header->next = (linked_list_header *) linked_list_init (header->element_size);
-      header->next->prev = header;
     }
     linked_list_set_element ((linked_list) header->next,
-                             (uint16_t) (element_num - (header->block_size / header->element_size)),
+                             element_num - (block_size / header->element_size),
                              element);
     return;
   }
diff --git a/jerry-core/parser/collections/linked-list.h b/jerry-core/parser/collections/linked-list.h
index 4147307e4..280492d91 100644
--- a/jerry-core/parser/collections/linked-list.h
+++ b/jerry-core/parser/collections/linked-list.h
@@ -23,7 +23,7 @@ typedef uint8_t* linked_list;
 
 linked_list linked_list_init (uint16_t);
 void linked_list_free (linked_list);
-void *linked_list_element (linked_list, uint16_t);
-void linked_list_set_element (linked_list, uint16_t, void *);
+void *linked_list_element (linked_list, size_t);
+void linked_list_set_element (linked_list, size_t, void *);
 
 #endif /* LINKED_LIST_H */
diff --git a/jerry-core/parser/collections/literal.h b/jerry-core/parser/collections/literal.h
index ea9cbf6e1..f8ace2beb 100644
--- a/jerry-core/parser/collections/literal.h
+++ b/jerry-core/parser/collections/literal.h
@@ -19,7 +19,7 @@
 #include "ecma-globals.h"
 #include "lp-string.h"
 
-typedef enum
+typedef enum __attr_packed___
 {
   LIT_UNKNOWN,
   LIT_STR,
diff --git a/jerry-core/parser/collections/tree.h b/jerry-core/parser/collections/tree.h
index bb5c2bad0..4261ddffc 100644
--- a/jerry-core/parser/collections/tree.h
+++ b/jerry-core/parser/collections/tree.h
@@ -18,13 +18,10 @@
 
 #include "linked-list.h"
 
-#define TREE_MAGIC 0x43
-
 typedef struct tree_header
 {
   struct tree_header *parent;
   linked_list children;
-  uint8_t magic;
   uint8_t children_num;
 }
 tree_header;
diff --git a/jerry-core/parser/js/lexer.h b/jerry-core/parser/js/lexer.h
index cf1deb59f..2497a5551 100644
--- a/jerry-core/parser/js/lexer.h
+++ b/jerry-core/parser/js/lexer.h
@@ -1,4 +1,4 @@
-/* Copyright 2014 Samsung Electronics Co., Ltd.
+/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,7 +22,7 @@
 #define INVALID_LITERAL UINT32_MAX
 
 /* Keywords.  */
-typedef enum
+typedef enum __attr_packed___
 {
   /* Not a keyword.  */
   KW_NONE = 0,
@@ -81,7 +81,7 @@ keyword;
 
 
 /* Type of tokens.  */
-typedef enum
+typedef enum __attr_packed___
 {
   TOK_EOF = 0, // End of file
   TOK_NAME, // Identifier
diff --git a/jerry-core/parser/js/literal.h b/jerry-core/parser/js/literal.h
index ea9cbf6e1..f8ace2beb 100644
--- a/jerry-core/parser/js/literal.h
+++ b/jerry-core/parser/js/literal.h
@@ -19,7 +19,7 @@
 #include "ecma-globals.h"
 #include "lp-string.h"
 
-typedef enum
+typedef enum __attr_packed___
 {
   LIT_UNKNOWN,
   LIT_STR,
diff --git a/jerry-core/parser/js/opcodes-dumper.h b/jerry-core/parser/js/opcodes-dumper.h
index 21fdeeaff..4789e804c 100644
--- a/jerry-core/parser/js/opcodes-dumper.h
+++ b/jerry-core/parser/js/opcodes-dumper.h
@@ -1,4 +1,4 @@
-/* Copyright 2014 Samsung Electronics Co., Ltd.
+/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,7 @@
 #include "ecma-globals.h"
 #include "lexer.h"
 
-typedef enum
+typedef enum __attr_packed___
 {
   OPERAND_LITERAL,
   OPERAND_TMP
@@ -39,7 +39,7 @@ typedef struct
 }
 operand;
 
-typedef enum
+typedef enum __attr_packed___
 {
   VARG_FUNC_DECL,
   VARG_FUNC_EXPR,
diff --git a/jerry-core/parser/js/scopes-tree.cpp b/jerry-core/parser/js/scopes-tree.cpp
index 33f077f11..6b7898880 100644
--- a/jerry-core/parser/js/scopes-tree.cpp
+++ b/jerry-core/parser/js/scopes-tree.cpp
@@ -30,7 +30,6 @@ static void
 assert_tree (scopes_tree t)
 {
   JERRY_ASSERT (t != NULL);
-  JERRY_ASSERT (t->t.magic == TREE_MAGIC);
 }
 
 static idx_t
@@ -648,7 +647,6 @@ scopes_tree_init (scopes_tree parent)
 {
   scopes_tree tree = (scopes_tree) mem_heap_alloc_block (sizeof (scopes_tree_int), MEM_HEAP_ALLOC_SHORT_TERM);
   memset (tree, 0, sizeof (scopes_tree_int));
-  tree->t.magic = TREE_MAGIC;
   tree->t.parent = (tree_header *) parent;
   tree->t.children = null_list;
   tree->t.children_num = 0;
diff --git a/jerry-core/parser/js/syntax-errors.h b/jerry-core/parser/js/syntax-errors.h
index ac2162ec2..bf82ddd00 100644
--- a/jerry-core/parser/js/syntax-errors.h
+++ b/jerry-core/parser/js/syntax-errors.h
@@ -79,7 +79,7 @@
 } while (0)
 #endif /* JERRY_NDEBUG */
 
-typedef enum
+typedef enum __attr_packed___
 {
   PROP_DATA,
   PROP_SET,