diff --git a/codebuild/coverage/coverage.yml b/codebuild/coverage/coverage.yml
index f82a3a98..51d8b0a6 100644
--- a/codebuild/coverage/coverage.yml
+++ b/codebuild/coverage/coverage.yml
@@ -10,5 +10,5 @@ phases:
       python: latest
   build:
     commands:
-      - pip install tox
+      - pip install "tox < 4.0"
       - tox
diff --git a/codebuild/python3.10.yml b/codebuild/python3.10.yml
index 4fe79318..a18185dc 100644
--- a/codebuild/python3.10.yml
+++ b/codebuild/python3.10.yml
@@ -16,5 +16,5 @@ phases:
     commands:
       - pyenv install 3.10.0
       - pyenv local 3.10.0
-      - pip install tox tox-pyenv
+      - pip install "tox < 4.0"
       - tox
diff --git a/codebuild/python3.5.yml b/codebuild/python3.5.yml
deleted file mode 100644
index e69de29b..00000000
diff --git a/codebuild/python3.6.yml b/codebuild/python3.6.yml
deleted file mode 100644
index e69de29b..00000000
diff --git a/codebuild/python3.7.yml b/codebuild/python3.7.yml
index 93e8a312..19a97151 100644
--- a/codebuild/python3.7.yml
+++ b/codebuild/python3.7.yml
@@ -28,5 +28,5 @@ phases:
       # The choice of versions should be reviewed.
       - pyenv install 3.7.12
       - pyenv local 3.7.12
-      - pip install tox tox-pyenv
+      - pip install "tox < 4.0"
       - tox
diff --git a/codebuild/python3.8.yml b/codebuild/python3.8.yml
index c0170f2a..cc7a821d 100644
--- a/codebuild/python3.8.yml
+++ b/codebuild/python3.8.yml
@@ -16,5 +16,5 @@ phases:
     commands:
       - pyenv install 3.8.12
       - pyenv local 3.8.12
-      - pip install tox tox-pyenv
+      - pip install "tox < 4.0"
       - tox
diff --git a/codebuild/python3.9.yml b/codebuild/python3.9.yml
index f4de17ef..8e5f609e 100644
--- a/codebuild/python3.9.yml
+++ b/codebuild/python3.9.yml
@@ -16,5 +16,5 @@ phases:
     commands:
       - pyenv install 3.9.7
       - pyenv local 3.9.7
-      - pip install tox tox-pyenv
+      - pip install "tox < 4.0"
       - tox
diff --git a/codebuild/release/prod-release.yml b/codebuild/release/prod-release.yml
index c729c96c..c8639c61 100644
--- a/codebuild/release/prod-release.yml
+++ b/codebuild/release/prod-release.yml
@@ -10,7 +10,7 @@ env:
 phases:
   install:
     commands:
-      - pip install tox
+      - pip install "tox < 4.0"
       - pip install --upgrade pip
     runtime-versions:
       python: latest
diff --git a/codebuild/release/test-release.yml b/codebuild/release/test-release.yml
index 1dc9feae..9d8fbed2 100644
--- a/codebuild/release/test-release.yml
+++ b/codebuild/release/test-release.yml
@@ -10,7 +10,7 @@ env:
 phases:
   install:
     commands:
-      - pip install tox
+      - pip install "tox < 4.0"
       - pip install --upgrade pip
     runtime-versions:
       python: latest
diff --git a/codebuild/release/validate.yml b/codebuild/release/validate.yml
index 7f0fda4b..f710aa5a 100644
--- a/codebuild/release/validate.yml
+++ b/codebuild/release/validate.yml
@@ -15,7 +15,7 @@ env:
 phases:
   install:
     commands:
-      - pip install tox
+      - pip install "tox < 4.0"
     runtime-versions:
       python: latest
   pre_build: