diff --git a/codec/decoder/core/src/au_parser.cpp b/codec/decoder/core/src/au_parser.cpp
index 7b9dbad1..0a8b2b70 100644
--- a/codec/decoder/core/src/au_parser.cpp
+++ b/codec/decoder/core/src/au_parser.cpp
@@ -37,24 +37,13 @@
  *
  *************************************************************************************
  */
-#include <string.h>
 #include "codec_def.h"
-#include "ls_defines.h"
-#include "macros.h"
 #include "au_parser.h"
 #include "decoder.h"
 #include "error_code.h"
-#include "dec_frame.h"
-#include "dec_golomb.h"
-#include "bit_stream.h"
-#include "utils.h"
-#include "codec_app_def.h"
 #include "memmgr_nal_unit.h"
 #include "decoder_core.h"
-#include "wels_common_basis.h"
 #include "decoder_core.h"
-#include "manage_dec_ref.h"
-#include "mem_align.h"
 
 namespace WelsDec {
 /*!
diff --git a/codec/decoder/core/src/bit_stream.cpp b/codec/decoder/core/src/bit_stream.cpp
index 36d935f8..2ddec2d6 100644
--- a/codec/decoder/core/src/bit_stream.cpp
+++ b/codec/decoder/core/src/bit_stream.cpp
@@ -38,7 +38,6 @@
  *************************************************************************************
  */
 #include "bit_stream.h"
-#include "macros.h"
 
 namespace WelsDec {
 
diff --git a/codec/decoder/core/src/deblocking.cpp b/codec/decoder/core/src/deblocking.cpp
index 4c997ed0..65876f19 100644
--- a/codec/decoder/core/src/deblocking.cpp
+++ b/codec/decoder/core/src/deblocking.cpp
@@ -40,7 +40,6 @@
 
 #include "deblocking.h"
 #include "cpu_core.h"
-#include "fmo.h"
 
 namespace WelsDec {
 
diff --git a/codec/decoder/core/src/decode_slice.cpp b/codec/decoder/core/src/decode_slice.cpp
index c56fb928..7ab71cfc 100644
--- a/codec/decoder/core/src/decode_slice.cpp
+++ b/codec/decoder/core/src/decode_slice.cpp
@@ -37,26 +37,17 @@
  *      08/09/2013 Modified
  *
  *****************************************************************************/
-#include <memory.h>
 
-#include "typedefs.h"
-#include "dec_golomb.h"
 
-#include "fmo.h"
 #include "deblocking.h"
-#include "utils.h"
 
 #include "decode_slice.h"
 
-#include "error_code.h"
-#include "decode_mb_aux.h"
 #include "parse_mb_syn_cavlc.h"
 #include "rec_mb.h"
 #include "mv_pred.h"
 
-#include "as264_common.h"
 #include "cpu_core.h"
-#include "expand_pic.h"
 
 namespace WelsDec {
 
diff --git a/codec/decoder/core/src/decoder.cpp b/codec/decoder/core/src/decoder.cpp
index 00e6462d..783c6d6f 100644
--- a/codec/decoder/core/src/decoder.cpp
+++ b/codec/decoder/core/src/decoder.cpp
@@ -37,30 +37,19 @@
  *
  *************************************************************************************
  */
-#include <string.h>
-#include "macros.h"
 #include "codec_def.h"
 #include "decoder.h"
-#include "error_code.h"
 #include "cpu.h"
-#include "cpu_core.h"
 #include "au_parser.h"
-#include "utils.h"
-#include "nal_prefix.h"
-#include "dec_frame.h"
-#include "pic_queue.h"
-#include "vlc_decoder.h"
 #include "get_intra_predictor.h"
 #include "rec_mb.h"
 #include "mc.h"
 #include "decode_mb_aux.h"
 #include "manage_dec_ref.h"
-#include "codec_app_def.h"
 #include "decoder_core.h"
 #include "deblocking.h"
 #include "expand_pic.h"
 #include "decode_slice.h"
-#include "crt_util_safe_x.h"	// Safe CRT routines like utils for cross platforms
 #include "mem_align.h"
 
 namespace WelsDec {
diff --git a/codec/decoder/core/src/decoder_core.cpp b/codec/decoder/core/src/decoder_core.cpp
index fec6c68d..76158e2c 100644
--- a/codec/decoder/core/src/decoder_core.cpp
+++ b/codec/decoder/core/src/decoder_core.cpp
@@ -31,25 +31,10 @@
  *	decoder_core.c:	Wels decoder framework core implementation
  */
 
-#include <string.h>
-#include "codec_def.h"
 #include "decoder_core.h"
-#include "typedefs.h"
-#include "wels_const.h"
-#include "wels_common_basis.h"
-#include "codec_app_def.h"
-#include "decoder_context.h"
-#include "dec_golomb.h"
-#include "bit_stream.h"
 #include "error_code.h"
-#include "parameter_sets.h"
-#include "fmo.h"
-#include "utils.h"
 #include "memmgr_nal_unit.h"
-#include "dec_frame.h"
 #include "au_parser.h"
-#include "pic_queue.h"
-#include "ls_defines.h"
 #include "decode_slice.h"
 #include "manage_dec_ref.h"
 #include "expand_pic.h"
diff --git a/codec/decoder/core/src/decoder_data_tables.cpp b/codec/decoder/core/src/decoder_data_tables.cpp
index a2c9e38f..ebc44bad 100644
--- a/codec/decoder/core/src/decoder_data_tables.cpp
+++ b/codec/decoder/core/src/decoder_data_tables.cpp
@@ -32,10 +32,8 @@
 
 // exp_data.c
 // export date cross various modules (.c)
-#include "typedefs.h"
 #include "wels_common_basis.h"
 #include "mb_cache.h"
-#include "utils.h"
 #include "vlc_decoder.h"
 
 namespace WelsDec {
diff --git a/codec/decoder/core/src/expand_pic.cpp b/codec/decoder/core/src/expand_pic.cpp
index 99518258..37c4a00c 100644
--- a/codec/decoder/core/src/expand_pic.cpp
+++ b/codec/decoder/core/src/expand_pic.cpp
@@ -30,9 +30,7 @@
  *
  */
 
-#include <string.h>
 
-#include "typedefs.h"
 #include "expand_pic.h"
 #include "cpu_core.h"
 
diff --git a/codec/decoder/core/src/fmo.cpp b/codec/decoder/core/src/fmo.cpp
index 633fd241..6c967359 100644
--- a/codec/decoder/core/src/fmo.cpp
+++ b/codec/decoder/core/src/fmo.cpp
@@ -37,11 +37,8 @@
  *
  *************************************************************************************
  */
-#include <string.h>
 
 #include "fmo.h"
-#include "macros.h"
-#include "utils.h"
 #include "mem_align.h"
 
 namespace WelsDec {
diff --git a/codec/decoder/core/src/manage_dec_ref.cpp b/codec/decoder/core/src/manage_dec_ref.cpp
index bb4b9c15..e750a7a5 100644
--- a/codec/decoder/core/src/manage_dec_ref.cpp
+++ b/codec/decoder/core/src/manage_dec_ref.cpp
@@ -38,12 +38,9 @@
  *      07/21/2008 Created
  *
  *****************************************************************************/
-#include <string.h>
 
 #include "manage_dec_ref.h"
 #include "error_code.h"
-#include "utils.h"
-#include "as264_common.h" // for LTR macro can be delete later
 
 namespace WelsDec {
 
diff --git a/codec/decoder/core/src/mc.cpp b/codec/decoder/core/src/mc.cpp
index 106f101d..3528b62d 100644
--- a/codec/decoder/core/src/mc.cpp
+++ b/codec/decoder/core/src/mc.cpp
@@ -38,7 +38,6 @@
  *************************************************************************************
  */
 
-#include "as264_common.h"
 #include "mc.h"
 
 #include "cpu_core.h"
diff --git a/codec/decoder/core/src/mem_align.cpp b/codec/decoder/core/src/mem_align.cpp
index 84f23f6f..b0dc5eb4 100644
--- a/codec/decoder/core/src/mem_align.cpp
+++ b/codec/decoder/core/src/mem_align.cpp
@@ -31,7 +31,6 @@
  */
 
 #include "mem_align.h"
-#include "crt_util_safe_x.h"
 
 namespace WelsDec {
 
diff --git a/codec/decoder/core/src/memmgr_nal_unit.cpp b/codec/decoder/core/src/memmgr_nal_unit.cpp
index 56bb159c..9fc741a1 100644
--- a/codec/decoder/core/src/memmgr_nal_unit.cpp
+++ b/codec/decoder/core/src/memmgr_nal_unit.cpp
@@ -39,7 +39,6 @@
  *
  *****************************************************************************/
 #include "memmgr_nal_unit.h"
-#include "utils.h"
 #include "mem_align.h"
 
 namespace WelsDec {
diff --git a/codec/decoder/core/src/parse_mb_syn_cavlc.cpp b/codec/decoder/core/src/parse_mb_syn_cavlc.cpp
index cf2a3a83..d45948a2 100644
--- a/codec/decoder/core/src/parse_mb_syn_cavlc.cpp
+++ b/codec/decoder/core/src/parse_mb_syn_cavlc.cpp
@@ -38,17 +38,10 @@
  *************************************************************************************
  */
 
-#include <string.h>
 
 #include "parse_mb_syn_cavlc.h"
 #include "error_code.h"
-#include "dec_golomb.h"
-#include "macros.h"
-#include "vlc_decoder.h"
-#include "bit_stream.h"
-#include "ls_defines.h"
 #include "mv_pred.h"
-#include "decode_slice.h"
 
 namespace WelsDec {
 
diff --git a/codec/decoder/core/src/pic_queue.cpp b/codec/decoder/core/src/pic_queue.cpp
index 4ce444cf..0069b828 100644
--- a/codec/decoder/core/src/pic_queue.cpp
+++ b/codec/decoder/core/src/pic_queue.cpp
@@ -37,11 +37,7 @@
  *
  *************************************************************************************
  */
-#include <string.h>
 #include "pic_queue.h"
-#include "wels_const.h"
-#include "utils.h"
-#include "macros.h"
 #include "decoder_context.h"
 #include "codec_def.h"
 #include "mem_align.h"
diff --git a/codec/decoder/core/src/rec_mb.cpp b/codec/decoder/core/src/rec_mb.cpp
index c34c2f94..1fea619f 100644
--- a/codec/decoder/core/src/rec_mb.cpp
+++ b/codec/decoder/core/src/rec_mb.cpp
@@ -37,14 +37,9 @@
  *
  *************************************************************************************
  */
-#include <memory.h>
 
-#include "macros.h"
 
 #include "rec_mb.h"
-#include "parse_mb_syn_cavlc.h"
-#include "get_intra_predictor.h"
-#include "decode_mb_aux.h"
 #include "decode_slice.h"
 
 namespace WelsDec {