diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index f36ed334..44745029 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -80,3 +80,22 @@ jobs:
             SublimeText/UnitTesting
       - uses: "./UnitTesting/actions/run-tests"
       - uses: "./UnitTesting/actions/run-syntax-tests"
+
+  test-package-control-extra-packages:
+    strategy:
+      fail-fast: false
+      matrix:
+        st-version: [3, 4]
+        os: ["ubuntu-latest", "macOS-latest", "windows-latest"]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v6
+      - uses: "./actions/setup"
+        with:
+          sublime-text-version: ${{ matrix.st-version }}
+          extra-packages: |
+            A File Icon
+      - name: Check package installed by Package Control
+        run: test -f "${SUBLIME_TEXT_PACKAGES%/}/../Installed Packages/A File Icon.sublime-package"
+        shell: bash
+      - uses: "./actions/run-tests"
diff --git a/README.md b/README.md
index b11109cc..b33a0610 100644
--- a/README.md
+++ b/README.md
@@ -336,6 +336,14 @@ jobs:
       - uses: codecov/codecov-action@v4
 ```
 
+`extra-packages` takes one package per line, in one of these forms:
+
+- `user/repo@ref` or `Package Name:user/repo@ref` clones the package from GitHub.
+  `@ref` is a branch, a tag or a tag prefix (e.g. `st3-`). Without it, the latest `x.y.z` tag is used.
+- `Package Name` (no `/`) lets Package Control install the package,
+  picking the latest release compatible with the Sublime Text build.
+  Requires `install-package-control: true` (the default).
+
 Check [this](https://github.com/randy3k/UnitTesting-example) for further examples.
 
 
diff --git a/actions/setup/action.yaml b/actions/setup/action.yaml
index 08edd100..b41783f9 100644
--- a/actions/setup/action.yaml
+++ b/actions/setup/action.yaml
@@ -48,6 +48,9 @@ inputs:
       or just `user/repo@ref` if the repo name is the same as the package name. `@ref` could
       be either a branch name, a tag name , or a prefix of tags e.g. `st3-` or simply left
       empty. If an exact match is not found, the latest tag is determined by semver x.y.z.
+      A line with just a package name (no `/`), e.g. `A File Icon`, installs the package via
+      Package Control, which picks the latest release compatible with the Sublime Text build.
+      This requires `install-package-control` to be enabled.
     required: false
   display:
     description: internal and experimental only
@@ -214,6 +217,7 @@ runs:
         fi
 
         # Install extra packages to to Packages/<Package>
+        PC_PACKAGES=""
         while read -r x; do
             if [[ "$x" =~ ^(.*):(.*)/([^@]*)@?(.*)$ ]]; then
                 PKG="${BASH_REMATCH[1]}"
@@ -225,12 +229,29 @@ runs:
                 USER="${BASH_REMATCH[1]}"
                 REPO="${BASH_REMATCH[2]}"
                 SHA="${BASH_REMATCH[3]}"
+            elif [ -n "$x" ]; then
+                # Plain package name, installed by Package Control
+                PC_PACKAGES+="$x"$'\n'
+                continue
             else
               continue
             fi
             InstallPackage "$PKG" "https://github.com/$USER/$REPO" "$SHA"
         done <<< "${{ inputs.extra-packages }}"
 
+        # Pass packages to be installed by Package Control to the next step
+        if [ -n "$PC_PACKAGES" ]; then
+            if [ "${{ inputs.install-package-control }}" != "true" ]; then
+                echo "::error::extra-packages lists packages to install via Package Control, but install-package-control is disabled."
+                exit 1
+            fi
+            {
+                echo "UNITTESTING_PC_PACKAGES<<UNITTESTING_PC_PACKAGES_EOF"
+                printf '%s' "$PC_PACKAGES"
+                echo "UNITTESTING_PC_PACKAGES_EOF"
+            } >> "$GITHUB_ENV"
+        fi
+
         # Install UnitTesting to Packages/UnitTesting if not yet exists
         if [ ! -d "$SUBLIME_TEXT_PACKAGES/UnitTesting" ]; then
             echo "Copy action's 'UnitTesting' to $SUBLIME_TEXT_PACKAGES/UnitTesting"
diff --git a/actions/setup/install_package_control.ps1 b/actions/setup/install_package_control.ps1
index affed857..e7d8ef23 100644
--- a/actions/setup/install_package_control.ps1
+++ b/actions/setup/install_package_control.ps1
@@ -26,6 +26,22 @@ if (-not (Test-Path $PC_SETTINGS)) {
     "{`"auto_upgrade`": false, `"ignore_vcs_packages`": true, `"remove_orphaned`": false, `"submit_usage`": false }" | Out-File -filepath $PC_SETTINGS -encoding utf8
 }
 
+# let Package Control install packages listed in `installed_packages` on startup
+if ($env:UNITTESTING_PC_PACKAGES) {
+    Write-Verbose "Adding packages to be installed by Package Control:"
+    $settings = Get-Content -Raw $PC_SETTINGS | ConvertFrom-Json
+    $names = @($settings.installed_packages | Where-Object { $_ })
+    foreach ($name in $env:UNITTESTING_PC_PACKAGES -split "`r?`n") {
+        $name = $name.Trim()
+        if ($name -and $names -notcontains $name) {
+            Write-Verbose "  $name"
+            $names += $name
+        }
+    }
+    $settings | Add-Member -NotePropertyName installed_packages -NotePropertyValue $names -Force
+    $settings | ConvertTo-Json | Out-File -filepath $PC_SETTINGS -encoding utf8
+}
+
 $PCH_PATH = "$STP\0_install_package_control_helper"
 New-Item -itemtype directory $PCH_PATH -force >$null
 
diff --git a/actions/setup/install_package_control.sh b/actions/setup/install_package_control.sh
index 7144a2ab..d3965451 100644
--- a/actions/setup/install_package_control.sh
+++ b/actions/setup/install_package_control.sh
@@ -55,6 +55,29 @@ if [ ! -f "$STP/User/Package Control.sublime-settings" ]; then
     echo '{"auto_upgrade": false, "ignore_vcs_packages": true, "remove_orphaned": false, "submit_usage": false }' > "$STP/User/Package Control.sublime-settings"
 fi
 
+# let Package Control install packages listed in `installed_packages` on startup
+if [ -n "$UNITTESTING_PC_PACKAGES" ]; then
+    echo Adding packages to be installed by Package Control:
+    printf '%s' "$UNITTESTING_PC_PACKAGES" | sed 's/^/  /'
+    python3 -B - "$STP/User/Package Control.sublime-settings" <<'EOF'
+import json
+import os
+import sys
+
+path = sys.argv[1]
+with open(path, encoding="utf-8") as f:
+    settings = json.load(f)
+names = settings.get("installed_packages", [])
+for name in os.environ["UNITTESTING_PC_PACKAGES"].splitlines():
+    name = name.strip()
+    if name and name not in names:
+        names.append(name)
+settings["installed_packages"] = names
+with open(path, "w", encoding="utf-8") as f:
+    json.dump(settings, f, indent=4)
+EOF
+fi
+
 PCH_PATH="$STP/0_install_package_control_helper"
 
 if [ ! -d "$PCH_PATH" ]; then
diff --git a/actions/setup/install_package_control_helper.py b/actions/setup/install_package_control_helper.py
index b22b714e..f996409e 100644
--- a/actions/setup/install_package_control_helper.py
+++ b/actions/setup/install_package_control_helper.py
@@ -44,12 +44,48 @@ def check_package_control():
         Wait for Package Control to be loaded.
         """
         if "Package Control" in sys.modules:
-            sublime.set_timeout(check_libraries, 2000)
+            sublime.set_timeout(check_packages, 2000)
         else:
             sublime.set_timeout(check_package_control, 2000)
 
     num_retries = 0
 
+    def retry(callback):
+        """
+        Schedule another check, return False if out of retries.
+        """
+        nonlocal num_retries
+
+        if num_retries < 20:
+            num_retries += 1
+            sublime.set_timeout(callback, 2000)
+            return True
+
+        return False
+
+    def check_packages():
+        """
+        Wait for Package Control to install missing packages.
+
+        PC4 automatically installs packages listed in `installed_packages`
+        at startup, before installing missing libraries.
+        """
+        package_control = sys.modules["Package Control"].package_control
+        manager = package_control.package_manager.PackageManager()
+        settings = sublime.load_settings("Package Control.sublime-settings")
+        missing_packages = set(settings.get("installed_packages", [])) - manager.list_packages()
+        if not missing_packages:
+            check_libraries()
+            return
+
+        if retry(check_packages):
+            return
+
+        log.write("missing packages:" + "\n")
+        log.write("\n".join("- " + name for name in sorted(missing_packages)) + "\n")
+        touch("failed")
+        kill_subl(restart=False)
+
     def check_libraries():
         """
         Wait for Package Control to finish bootstrapping.
@@ -61,17 +97,13 @@ def check_libraries():
         manager = package_control.package_manager.PackageManager()
         missing_libraries = manager.find_missing_libraries()
         if missing_libraries:
-            nonlocal num_retries
-
-            if num_retries < 10:
-                num_retries += 1
-                sublime.set_timeout(check_libraries, 2000)
+            if retry(check_libraries):
                 return
 
             log.write("missing libraries:" + "\n")
             log.write(
                 "\n".join(
-                    "- {lib.name} for Python {lib.python_version}".format(lib)
+                    "- {lib.name} for Python {lib.python_version}".format(lib=lib)
                     for lib in sorted(missing_libraries)
                 )
                 + "\n"