diff --git a/jerry-core/config.h b/jerry-core/config.h
index 4d0960747..8e10ae0c6 100644
--- a/jerry-core/config.h
+++ b/jerry-core/config.h
@@ -26,13 +26,6 @@
  */
 #define CONFIG_MEM_STACK_LIMIT (4096)
 
-/**
- * Size of pool chunk
- *
- * Should not be less than size of any of ECMA Object Model's data types.
- */
-#define CONFIG_MEM_POOL_CHUNK_SIZE (8)
-
 /**
  * Size of heap
  */
@@ -50,26 +43,6 @@
  */
 #define CONFIG_MEM_HEAP_DESIRED_LIMIT (JERRY_MIN (CONFIG_MEM_HEAP_AREA_SIZE / 32, CONFIG_MEM_HEAP_MAX_LIMIT))
 
-/**
- * Number of lower bits in key of literal hash table.
- */
-#define CONFIG_LITERAL_HASH_TABLE_KEY_BITS (7)
-
-/**
- * Width of fields used for holding counter of references to ecma-strings and ecma-objects
- *
- * The option affects maximum number of simultaneously existing:
- *  - references to one string;
- *  - stack references to one object
- * The number is ((2 ^ CONFIG_ECMA_REFERENCE_COUNTER_WIDTH) - 1).
- *
- * Also the option affects size of ECMA Object Model's data types.
- * In any case size of any of the types should not exceed CONFIG_MEM_POOL_CHUNK_SIZE.
- */
-#define CONFIG_ECMA_REFERENCE_COUNTER_WIDTH (12)
-
-#define CONFIG_ECMA_REFERENCE_COUNTER_LIMIT ((1u << CONFIG_ECMA_REFERENCE_COUNTER_WIDTH) - 1u)
-
 /**
  * Use 32-bit/64-bit float for ecma-numbers
  */
@@ -90,22 +63,6 @@
 #  error "Date does not support float32"
 #endif
 
-/**
- * Representation for ecma-characters
- */
-#define CONFIG_ECMA_CHAR_ASCII (1) /* ASCII */
-#define CONFIG_ECMA_CHAR_UTF16 (2) /* UTF-16 */
-
-#ifndef CONFIG_ECMA_CHAR_ENCODING
-# define CONFIG_ECMA_CHAR_ENCODING CONFIG_ECMA_CHAR_ASCII
-#else /* CONFIG_ECMA_CHAR_ENCODING */
-# if (CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_ASCII \
-      && CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_UTF16)
-#  error "ECMA-char encoding is configured incorrectly"
-# endif /* CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_ASCII
-           && CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_UTF16 */
-#endif /* !CONFIG_ECMA_CHAR_ENCODING */
-
 /**
  * Disable ECMA lookup cache
  */
@@ -136,14 +93,4 @@
  */
 #define CONFIG_VM_STACK_FRAME_INLINED_VALUES_NUMBER (16)
 
-/**
- * Run GC after execution of each byte-code instruction
- */
-// #define CONFIG_VM_RUN_GC_AFTER_EACH_OPCODE
-
-/**
- * Flag, indicating whether to enable parser-time byte-code optimizations
- */
-#define CONFIG_PARSER_ENABLE_PARSE_TIME_BYTE_CODE_OPTIMIZER
-
 #endif /* !CONFIG_H */
diff --git a/jerry-core/ecma/base/ecma-helpers-errol.c b/jerry-core/ecma/base/ecma-helpers-errol.c
index 4efcc9d7c..5da88489e 100644
--- a/jerry-core/ecma/base/ecma-helpers-errol.c
+++ b/jerry-core/ecma/base/ecma-helpers-errol.c
@@ -38,7 +38,6 @@
 
 #include <math.h>
 
-#include "config.h"
 #include "ecma-helpers.h"
 
 /** \addtogroup ecma ECMA
diff --git a/jerry-core/vm/vm-stack.h b/jerry-core/vm/vm-stack.h
index de15b855f..0f921162e 100644
--- a/jerry-core/vm/vm-stack.h
+++ b/jerry-core/vm/vm-stack.h
@@ -16,7 +16,6 @@
 #ifndef VM_STACK_H
 #define VM_STACK_H
 
-#include "config.h"
 #include "ecma-globals.h"
 
 /** \addtogroup vm Virtual machine