diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
new file mode 100644
index 000000000..b23996804
--- /dev/null
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,22 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.163.1/containers/python-3/.devcontainer/base.Dockerfile
+
+# [Choice] Python version: 3, 3.9, 3.8, 3.7, 3.6
+ARG VARIANT="3"
+FROM mcr.microsoft.com/vscode/devcontainers/python:0-${VARIANT}
+
+# [Option] Install Node.js
+ARG INSTALL_NODE="true"
+ARG NODE_VERSION="lts/*"
+RUN if [ "${INSTALL_NODE}" = "true" ]; then su vscode -c "umask 0002 && . /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1"; fi
+
+# [Optional] If your pip requirements rarely change, uncomment this section to add them to the image.
+# COPY requirements.txt /tmp/pip-tmp/
+# RUN pip3 --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
+#    && rm -rf /tmp/pip-tmp
+
+# [Optional] Uncomment this section to install additional OS packages.
+# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+#     && apt-get -y install --no-install-recommends <your-package-list-here>
+
+# [Optional] Uncomment this line to install global node packages.
+# RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g <your-package-here>" 2>&1
\ No newline at end of file
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100644
index 000000000..f2e882058
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,47 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.163.1/containers/python-3
+{
+	"name": "Python 3",
+	"build": {
+		"dockerfile": "Dockerfile",
+		"context": "..",
+		"args": { 
+			// Update 'VARIANT' to pick a Python version: 3, 3.6, 3.7, 3.8, 3.9
+			"VARIANT": "3.9",
+			// Options
+			"INSTALL_NODE": "false",
+			"NODE_VERSION": "lts/*"
+		}
+	},
+
+	// Set *default* container specific settings.json values on container create.
+	"settings": { 
+		"terminal.integrated.shell.linux": "/bin/bash",
+		"python.pythonPath": "/usr/local/bin/python",
+		"python.linting.enabled": true,
+		"python.linting.pylintEnabled": true,
+		"python.formatting.autopep8Path": "/usr/local/py-utils/bin/autopep8",
+		"python.formatting.blackPath": "/usr/local/py-utils/bin/black",
+		"python.formatting.yapfPath": "/usr/local/py-utils/bin/yapf",
+		"python.linting.banditPath": "/usr/local/py-utils/bin/bandit",
+		"python.linting.flake8Path": "/usr/local/py-utils/bin/flake8",
+		"python.linting.mypyPath": "/usr/local/py-utils/bin/mypy",
+		"python.linting.pycodestylePath": "/usr/local/py-utils/bin/pycodestyle",
+		"python.linting.pydocstylePath": "/usr/local/py-utils/bin/pydocstyle",
+		"python.linting.pylintPath": "/usr/local/py-utils/bin/pylint"
+	},
+
+	// Add the IDs of extensions you want installed when the container is created.
+	"extensions": [
+		"ms-python.python"
+	],
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	"postCreateCommand": "pip3 install -r requirements.txt && python3 setup.py develop",
+
+	// Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+	//"remoteUser": "vscode"
+}
diff --git a/README.md b/README.md
index 46a1d24b9..77aa133f8 100644
--- a/README.md
+++ b/README.md
@@ -236,6 +236,7 @@ following rules are enabled by default:
 * `git_help_aliased` &ndash; fixes `git help <alias>` commands replacing <alias> with the aliased command;
 * `git_hook_bypass` &ndash; adds `--no-verify` flag previous to `git am`, `git commit`, or `git push` command;
 * `git_lfs_mistype` &ndash; fixes mistyped `git lfs <command>` commands;
+* `git_main_master` &ndash; fixes incorrect branch name between `main` and `master`
 * `git_merge` &ndash; adds remote to branch names;
 * `git_merge_unrelated` &ndash; adds `--allow-unrelated-histories` when required
 * `git_not_command` &ndash; fixes wrong git commands like `git brnch`;
diff --git a/tests/rules/test_git_main_master.py b/tests/rules/test_git_main_master.py
new file mode 100644
index 000000000..7e5733401
--- /dev/null
+++ b/tests/rules/test_git_main_master.py
@@ -0,0 +1,23 @@
+import pytest
+from thefuck.rules.git_main_master import match, get_new_command
+from thefuck.types import Command
+
+
+output = 'error: pathspec \'%s\' did not match any file(s) known to git'
+
+
+def test_match():
+    assert match(Command('git checkout main', output % ('main')))
+    assert match(Command('git checkout master', output % ('master')))
+    assert not match(Command('git checkout master', ''))
+    assert not match(Command('git checkout main', ''))
+    assert not match(Command('git checkout wibble', output % ('wibble')))
+
+
+@pytest.mark.parametrize('command, new_command', [
+    (Command('git checkout main', output % ('main')),
+     'git checkout master'),
+    (Command('git checkout master', output % ('master')),
+     'git checkout main')])
+def test_get_new_command(command, new_command):
+    assert get_new_command(command) == new_command
diff --git a/thefuck/rules/git_main_master.py b/thefuck/rules/git_main_master.py
new file mode 100644
index 000000000..4879fc3d4
--- /dev/null
+++ b/thefuck/rules/git_main_master.py
@@ -0,0 +1,14 @@
+from thefuck.specific.git import git_support
+
+
+@git_support
+def match(command):
+    return "'master'" in command.output.lower() or "'main'" in command.output.lower()
+
+
+@git_support
+def get_new_command(command):
+    if "'master'" in command.output.lower():
+        return command.script.replace("master", "main")
+    else:
+        return command.script.replace("main", "master")