diff --git a/.github/workflows/ci_on_centos7.yml b/.github/workflows/ci_on_centos7_yml.eol
similarity index 100%
rename from .github/workflows/ci_on_centos7.yml
rename to .github/workflows/ci_on_centos7_yml.eol
diff --git a/.gitignore b/.gitignore
index d2d9850cfcb..ba5301179ca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,6 +18,7 @@ tmp*
 __pycache__/
 check_autopep8
 .coverage
+.coverage.*
 htmlcov
 coverage.xml*
 test_utils/bats-core/
diff --git a/README.md b/README.md
index 7634a246d21..c893b8de83e 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,6 @@
 |ubuntu/python3.8/pip|||[![ci on ubuntu](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml?query=branch%3Amaster)|[![ci on ubuntu](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml?query=branch%3Amaster)|
 |ubuntu/python3.7/pip|[![ci on ubuntu](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml?query=branch%3Amaster)|[![ci on ubuntu](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_ubuntu.yml?query=branch%3Amaster)|||
 |debian11/python3.10/conda||[![ci on debian11](https://github.com/espnet/espnet/actions/workflows/ci_on_debian11.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_debian11.yml?query=branch%3Amaster)|||
-|centos7/python3.10/conda||[![ci on centos7](https://github.com/espnet/espnet/actions/workflows/ci_on_centos7.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_centos7.yml?query=branch%3Amaster)|||
 |windows/python3.10/pip||||[![ci on windows](https://github.com/espnet/espnet/actions/workflows/ci_on_windows.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_windows.yml?query=branch%3Amaster)|
 |macos/python3.10/pip||||[![ci on macos](https://github.com/espnet/espnet/actions/workflows/ci_on_macos.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_macos.yml?query=branch%3Amaster)|
 |macos/python3.10/conda||||[![ci on macos](https://github.com/espnet/espnet/actions/workflows/ci_on_macos.yml/badge.svg)](https://github.com/espnet/espnet/actions/workflows/ci_on_macos.yml?query=branch%3Amaster)|
diff --git a/tools/Makefile b/tools/Makefile
index 8a7a22e8c06..0a1ce7272b8 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -273,5 +273,7 @@ clean_extra:
 	rm -rf hts_engine_API.done open_jtalk.done pyopenjtalk.done
 	rm -rf muskits.done
 	rm -rf rvad_fast.done
+	rm -rf chainer espeak-ng festival MBROLA ParallelWaveGAN
+	rm -rf py3mmseg sctk* speech_tools sph2pipe* ._mwerSegmenter
 	rm -rf nkf mecab swig moses mwerSegmenter
 	rm -rf PESQ PESQ.zip
diff --git a/tools/installers/install_fairseq.sh b/tools/installers/install_fairseq.sh
index 61824378f6d..71a613621bf 100755
--- a/tools/installers/install_fairseq.sh
+++ b/tools/installers/install_fairseq.sh
@@ -39,14 +39,8 @@ echo "[INFO] torch_version=${torch_version}"
 if "$(pt_plus 1.8.0)" && "${python_36_plus}"; then
 
     rm -rf fairseq
-
-    # FairSeq Commit id when making this PR: `commit 313ff0581561c7725ea9430321d6af2901573dfb`
-    # git clone --depth 1 https://github.com/pytorch/fairseq.git
-    # TODO(jiatong): to fix after the issue #4035 is fixed in fairseq
-    git clone https://github.com/pytorch/fairseq.git
-    cd fairseq
-    git checkout -b sync_commit 313ff0581561c7725ea9430321d6af2901573dfb
-    cd ..
+    # NOTE(nelson): using custom fairseq for espnet
+    git clone https://github.com/espnet/fairseq.git
     python3 -m pip install --editable ./fairseq
     python3 -m pip install filelock