diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 58bc29c..8801b79 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,7 +16,7 @@ jobs:
           - "py37-pytestlatest"
           - "py38-pytestlatest"
           - "py39-pytestlatest"
-          - "py38-pytestmaster"
+          - "py38-pytestmain"
           - "py38-psutil"
           - "linting"
 
@@ -32,7 +32,7 @@ jobs:
             python: "3.8"
           - tox_env: "py39-pytestlatest"
             python: "3.9"
-          - tox_env: "py38-pytestmaster"
+          - tox_env: "py38-pytestmain"
             python: "3.8"
           - tox_env: "py38-psutil"
             python: "3.8"
diff --git a/changelog/643.trivial.rst b/changelog/643.trivial.rst
new file mode 100644
index 0000000..927d262
--- /dev/null
+++ b/changelog/643.trivial.rst
@@ -0,0 +1 @@
+Use 'main' to refer to pytest default branch in tox env names.
diff --git a/tox.ini b/tox.ini
index 9dc2b84..78f3bed 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,14 +2,14 @@
 envlist=
   linting
   py{35,36,37,38,39}-pytestlatest
-  py38-pytestmaster
+  py38-pytestmain
   py38-psutil
 
 [testenv]
 extras = testing
 deps =
   pytestlatest: pytest
-  pytestmaster: git+https://github.com/pytest-dev/pytest.git@main
+  pytestmain: git+https://github.com/pytest-dev/pytest.git
 commands=
   pytest {posargs}