diff --git a/.docker-config/php/Dockerfile b/.docker-config/php/Dockerfile
index 3896cfd..b897029 100755
--- a/.docker-config/php/Dockerfile
+++ b/.docker-config/php/Dockerfile
@@ -12,6 +12,8 @@ RUN chmod a+x run_queue.sh \
     chown -R www-data:www-data /var/www/project
 COPY ./composer_install.sh .
 RUN chmod a+x composer_install.sh
+COPY ./banner_message.sh .
+RUN chmod a+x banner_message.sh
 
 WORKDIR /var/www/project
 
diff --git a/.docker-config/php/banner_message.sh b/.docker-config/php/banner_message.sh
new file mode 100755
index 0000000..f6dbc33
--- /dev/null
+++ b/.docker-config/php/banner_message.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+# Banner Message shell script
+#
+# Display a banner message to let the user know the environment is ready for use
+#
+# @author    nystudio107
+# @copyright Copyright (c) 2023 nystudio107
+# @link      https://nystudio107.com/
+# @license   MIT
+
+# Rewrite the PRIMARY_SITE_URL env var if we're running in Codespaces
+if [[ ! ${CODESPACES:-"unset"} == "unset" ]]; then
+    export PRIMARY_SITE_URL="https://${CODESPACE_NAME}-${DEV_SERVER_PORT}.preview.app.github.dev/"
+fi
+# Banner message
+sleep 1
+echo "### Your Craft site is ready!"
+echo "Frontend URL: ${PRIMARY_SITE_URL}"
+echo "CP URL: ${PRIMARY_SITE_URL}admin"
+echo "CP User: ${CRAFT_CP_USER}"
+echo "CP Password: ${CRAFT_CP_PASSWORD}"
diff --git a/.docker-config/php/composer_install.sh b/.docker-config/php/composer_install.sh
index c045073..d646d2f 100755
--- a/.docker-config/php/composer_install.sh
+++ b/.docker-config/php/composer_install.sh
@@ -6,7 +6,7 @@
 # the `vendor/` directory is not present`
 #
 # @author    nystudio107
-# @copyright Copyright (c) 2022 nystudio107
+# @copyright Copyright (c) 2023 nystudio107
 # @link      https://nystudio107.com/
 # @license   MIT
 
@@ -28,9 +28,4 @@ if [ ! -f "composer.lock" ] || [ ! -d "vendor" ] || [ ! -f "vendor/autoload.php"
     su-exec www-data php craft up
 fi
 # Banner message
-sleep 1
-echo "### Your Craft site is ready!"
-echo "Frontend URL: ${PRIMARY_SITE_URL}"
-echo "CP URL: ${PRIMARY_SITE_URL}admin"
-echo "CP User: ${CRAFT_CP_USER}"
-echo "CP Password: ${CRAFT_CP_PASSWORD}"
+source '/var/www/banner_message.sh'
diff --git a/.docker-config/php/run_queue.sh b/.docker-config/php/run_queue.sh
index 66a2c86..755a78a 100755
--- a/.docker-config/php/run_queue.sh
+++ b/.docker-config/php/run_queue.sh
@@ -8,7 +8,7 @@
 # then runs the queue listener that listens for and runs pending queue jobs
 #
 # @author    nystudio107
-# @copyright Copyright (c) 2022 nystudio107
+# @copyright Copyright (c) 2023 nystudio107
 # @link      https://nystudio107.com/
 # @license   MIT
 
@@ -31,11 +31,6 @@ chown -R www-data:www-data /var/www/project/web/cpresources
 # Run any pending migrations/project config changes
 su-exec www-data php craft up
 # Banner message
-sleep 1
-echo "### Your Craft site is ready!"
-echo "Frontend URL: ${PRIMARY_SITE_URL}"
-echo "CP URL: ${PRIMARY_SITE_URL}admin"
-echo "CP User: ${CRAFT_CP_USER}"
-echo "CP Password: ${CRAFT_CP_PASSWORD}"
+source '/var/www/banner_message.sh'
 # Run a queue listener
 su-exec www-data php craft queue/listen 10
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b139def..9449e4a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # nystudio107/spin-up-craft Change Log
 
+## 1.0.5 - 2023.02.14
+### Added
+* Detect when we're running in Codespaces, and swap in the dynamic URL for the `PRIMARY_SITE_URL` env var automatically
+
+### Changed
+* Refactor the banner to a separate `banner_message.sh`
+
 ## 1.0.4 - 2023.02.08
 ### Added
 *  Add PHP 8.1 as the default image
diff --git a/config/general.php b/config/general.php
index 965ca65..ab655db 100644
--- a/config/general.php
+++ b/config/general.php
@@ -11,6 +11,16 @@
 use craft\config\GeneralConfig;
 use craft\helpers\App;
 
+// Rewrite the PRIMARY_SITE_URL env var if we're running in Codespaces
+if (App::env('CODESPACES')) {
+    // putenv() only affects the OS's environment, so set it directly
+    $_ENV['PRIMARY_SITE_URL'] = $_SERVER['PRIMARY_SITE_URL'] = sprintf(
+        "https://%s-%s.preview.app.github.dev/",
+        App::env('CODESPACE_NAME'),
+        App::env('DEV_SERVER_PORT')
+    );
+}
+
 return GeneralConfig::create()
     ->runQueueAutomatically(false)
     // Set the default week start day for date pickers (0 = Sunday, 1 = Monday, etc.)