diff --git a/.github/workflows/standards-and-tests.yml b/.github/workflows/standards-and-tests.yml
index d17254d..dcdec0c 100644
--- a/.github/workflows/standards-and-tests.yml
+++ b/.github/workflows/standards-and-tests.yml
@@ -13,14 +13,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [ 7.4, 8.0 ]
+        php: [ 8.0, 8.1 ]
         os: [ ubuntu-20.04 ]
-        wordpress: [ 6.0.3, latest ]
+        wordpress: [ 6.1.1, latest ]
         include:
           - experimental: true
           - experimental: false
             php: 8.0
-            wordpress: 6.0.3
+            wordpress: 6.1.1
 
     name: Test - PHP ${{ matrix.php }} - WP ${{ matrix.wordpress }}
 
diff --git a/.github/workflows/update-pot.yml b/.github/workflows/update-pot.yml
index fa49f3a..4e29c52 100644
--- a/.github/workflows/update-pot.yml
+++ b/.github/workflows/update-pot.yml
@@ -17,7 +17,7 @@ jobs:
     - name: Setup PHP with tools
       uses: shivammathur/setup-php@v2
       with:
-        php-version: '7.4'
+        php-version: '8.0'
         tools: composer, wp-cli/wp-cli-bundle
     - name: Update POT file
       run: wp i18n make-pot . languages/pressbooks-aldine.pot --domain=pressbooks-aldine --slug=pressbooks-aldine --package-name="Aldine" --headers="{\"Report-Msgid-Bugs-To\":\"https://github.com/pressbooks/pressbooks-aldine/issues\"}"
diff --git a/.github/workflows/update-translations.yml b/.github/workflows/update-translations.yml
index 39e3a66..f174a25 100644
--- a/.github/workflows/update-translations.yml
+++ b/.github/workflows/update-translations.yml
@@ -18,7 +18,7 @@ jobs:
     - name: Setup PHP with tools
       uses: shivammathur/setup-php@v2
       with:
-        php-version: '7.4'
+        php-version: '8.0'
         tools: composer, wp-cli/wp-cli-bundle
     - name: Generate MO files
       run: wp i18n make-mo languages
diff --git a/README.md b/README.md
index 658fca0..81aadcf 100644
--- a/README.md
+++ b/README.md
@@ -10,10 +10,10 @@
 
 Contributors: conner_bw, greatislander, steelwagstaff
 Tags: publishing, catalog, pressbooks, default-theme
-Requires at least: 6.0.3 
-Tested up to: 6.0.3 
-Stable tag: 1.17.0
-Requires PHP: 7.4
+Requires at least: 6.1.1 
+Tested up to: 6.1.1 
+Stable tag: 1.18.0
+Requires PHP: 8.0
 License: GNU General Public License v3 or later 
 License URI: https://www.gnu.org/licenses/gpl-3.0.html
 
@@ -31,12 +31,15 @@ Aldine is the default theme for the home page of [Pressbooks](https://pressbooks
 
 ## Changelog
 
-### 1.17.0
+### 1.18.0
 
-* See: https://github.com/pressbooks/pressbooks-aldine/releases/tag/1.17.0
+* See: https://github.com/pressbooks/pressbooks-aldine/releases/tag/1.18.0
 * Full release history available at: https://github.com/pressbooks/pressbooks-aldine/releases
 
-## Upgrade Notice
+## Upgrade Notices
+### 1.18.0
+- Aldine requires PHP >= 8.0
+- Aldine requires Pressbooks >= 6.4.0
 
 ### 1.14.1
 
diff --git a/composer.json b/composer.json
index f4e2acc..184f50f 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,7 @@
 		}
 	},
 	"require": {
-		"php": "^7.4|8.0.*",
+		"php": "^8.0",
 		"composer/installers": "^2",
 		"phpcompatibility/php-compatibility": "^9.3",
 		"pressbooks/mix": "^2.1",
diff --git a/style.css b/style.css
index 81ce436..662649a 100644
--- a/style.css
+++ b/style.css
@@ -5,10 +5,10 @@ Author:				Pressbooks (Book Oven Inc.)
 Author URI:			https://pressbooks.org
 Description:		Aldine is the default theme for the home page of Pressbooks networks. It is named for the Aldine Press, founded by Aldus Manutius in 1494, who is regarded by many as the world’s first publisher.
 Tags:				publishing, catalog, pressbooks, default-theme
-Version:			1.17.0
-Requires at least:	6.0.3
-Tested up to:		6.0.3
-Requires PHP:		7.4
+Version:			1.18.0
+Requires at least:	6.1.1
+Tested up to:		6.1.1
+Requires PHP:		8.0
 License:			GNU GPL v3 or later
 License URI:		https://github.com/pressbooks/pressbooks-aldine/tree/master/LICENSE.md
 Text Domain:		pressbooks-aldine