diff --git a/functions.php b/functions.php
index 0d615c9..96d0998 100644
--- a/functions.php
+++ b/functions.php
@@ -10,7 +10,22 @@
  * @link    https://www.christophherr.com/
  */
 
-namespace ChristophHerr\Prometheus2;
+/**
+ * Get the version of the Genesis framework.
+ *
+ * @since 2.0
+ *
+ * @return string
+ */
+function prometheus_2_get_genesis_version() {
+	return wp_get_theme( 'genesis' )->get( 'Version' );
+}
+
+// Check minimum requirements.
+if ( version_compare( $GLOBALS['wp_version'], '4.8', '<' ) || version_compare( PHP_VERSION, '5.6', '<' ) || version_compare( prometheus_2_get_genesis_version(), '2.6', '<' ) ) {
+	require_once 'lib/minimum-requirements.php';
+	return;
+}
 
 // Start the Child Theme.
 require_once 'lib/init.php';
diff --git a/languages/prometheus-2.pot b/languages/prometheus-2.pot
index c6c820d..11a3015 100644
--- a/languages/prometheus-2.pot
+++ b/languages/prometheus-2.pot
@@ -55,6 +55,41 @@ msgstr ""
 msgid "The maximum width of the logo in pixels."
 msgstr ""
 
+#. translators: 1 is the required Genesis Version, 2 is the required WordPress version, 3 is the required PHP version, 4 is the user's current Genesis version, 5 is the user's current WordPress version and 6 is the user's current PHP version.
+#: lib/minimum-requirements.php:79
+msgid "Prometheus 2 cannot be activated because it requires Genesis version %1$s, WordPress version %2$s and PHP version %3$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %4$s, WordPress version %5$s and PHP version %6$s. Please upgrade Genesis, WordPress and PHP and try again."
+msgstr ""
+
+#. translators: 1 is the required WordPress version, 2 is the required PHP version, 3 is the user's current WordPress version amd 4 is the user's current PHP version.
+#: lib/minimum-requirements.php:90
+msgid "Prometheus 2 cannot be activated because it requires WordPress version %1$s and PHP version %2$s. The Genesis Framework (parent theme) has been activated instead. You are running WordPress version %3$s and PHP version %4$s. Please upgrade WordPress and PHP and try again."
+msgstr ""
+
+#. translators: 1 is the required Genesis version, 2 is the required WordPress version, 3 is the user's current Genesis version and 4 is the user's current WordPress version.
+#: lib/minimum-requirements.php:99
+msgid "Prometheus 2 was not activated because it requires Genesis version %1$s and WordPress version %2$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %3$s and WordPress version %4$s. Please upgrade Genesis and WordPress and try again."
+msgstr ""
+
+#. translators: 1 is the required Genesis version, 2 is the required PHP version, 3 is the user's current Genesis version and 4 is the user's current PHP version.
+#: lib/minimum-requirements.php:108
+msgid "Prometheus 2 was not activated because it requires Genesis version %1$s and PHP version of %2$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %3$s and PHP version %4$s. Please upgrade Genesis and PHP and try again."
+msgstr ""
+
+#. translators: 1 is the required WordPress version and 2 is the user's current WordPress version.
+#: lib/minimum-requirements.php:117
+msgid "Prometheus 2 was not activated because it requires WordPress version %1$s. The Genesis Framework (parent theme) has been activated instead. You are running WordPress version %2$s. Please upgrade WordPress and try again."
+msgstr ""
+
+#. translators: 1 is the required PHP version and 2 is the user's current PHP version.
+#: lib/minimum-requirements.php:124
+msgid "Prometheus 2 was not activated because it requires PHP version %1$s. The Genesis Framework (parent theme) has been activated instead. You are running PHP version %2$s. Please upgrade PHP and try again."
+msgstr ""
+
+#. translators: 1 is the required Genesis version and 2 is the user's current Genesis version.
+#: lib/minimum-requirements.php:131
+msgid "Prometheus 2 was not activated because it requires Genesis version %1$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %2$s. Please upgrade Genesis and try again."
+msgstr ""
+
 #: lib/plugins/woocommerce/woocommerce-setup.php:67
 msgid "Previous Page"
 msgstr ""
diff --git a/lib/minimum-requirements.php b/lib/minimum-requirements.php
new file mode 100644
index 0000000..8d79eaf
--- /dev/null
+++ b/lib/minimum-requirements.php
@@ -0,0 +1,137 @@
+<?php
+/**
+ * Handle when minimum requirements are not met.
+ *
+ * @package     ChristophHerr\Prometheus2
+ * @since       2.0.0
+ * @author      Christoph Herr
+ * @link        https://www.christophherr.com
+ * @license     GNU General Public License 2+
+ */
+
+add_action( 'after_switch_theme', 'prometheus_2_switch_theme' );
+/**
+ * Switch to the Genesis parent theme after the theme has been activated.
+ *
+ * @since 2.0.0
+ *
+ * @return void
+ */
+function prometheus_2_switch_theme() {
+	switch_theme( 'genesis' );
+	unset( $_GET['activated'] );
+	add_action( 'admin_notices', 'prometheus_2_show_deactivation_and_upgrade_notice' );
+}
+
+add_action( 'load-customize.php', 'prometheus_2_do_not_load_customizer' );
+/**
+ * Don't load the Customizer.
+ *
+ * @since 2.0.0
+ *
+ * @return void
+ */
+function prometheus_2_do_not_load_customizer() {
+	wp_die( esc_html( prometheus_2_upgrade_message() ), '', array( 'back_link' => true ) );
+}
+
+add_action( 'template_redirect', 'prometheus_2_do_not_load_customizer_preview' );
+/**
+ * Don't load the Customizer preview on installs prior to WordPress 4.7.
+ *
+ * @since 2.0.0
+ *
+ * @return void
+ */
+function prometheus_2_do_not_load_customizer_preview() {
+	if ( isset( $_GET['preview'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.NoNonceVerification -- Just checking, no processing going on.
+		wp_die( esc_html( prometheus_2_upgrade_message() ) );
+	}
+}
+
+/**
+ * Show an admin notice.
+ *
+ * @since 2.0.0
+ *
+ * @return void
+ */
+function prometheus_2_show_deactivation_and_upgrade_notice() {
+	printf( '<div class="error"><p>%s</p></div>', esc_html( prometheus_2_upgrade_message() ) );
+}
+
+/**
+ * Content of the admin notice detailing that the theme was not activated and which requirement wasn't met.
+ *
+ * @since 2.0.0
+ *
+ * @return string
+ */
+function prometheus_2_upgrade_message() {
+	$genesis_version         = prometheus_2_get_genesis_version();
+	$compare_wp_version      = version_compare( $GLOBALS['wp_version'], '4.8', '<' );
+	$compare_php_version     = version_compare( PHP_VERSION, '5.6', '<' );
+	$compare_genesis_version = version_compare( $genesis_version, '2.6', '<' );
+
+	if ( $compare_wp_version && $compare_php_version && $compare_genesis_version ) {
+		return sprintf(
+			// Translators: 1 is the required Genesis Version, 2 is the required WordPress version, 3 is the required PHP version, 4 is the user's current Genesis version, 5 is the user's current WordPress version and 6 is the user's current PHP version.
+			__( 'Prometheus 2 cannot be activated because it requires Genesis version %1$s, WordPress version %2$s and PHP version %3$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %4$s, WordPress version %5$s and PHP version %6$s. Please upgrade Genesis, WordPress and PHP and try again.', 'prometheus2' ),
+			'2.6',
+			'4.9.6',
+			'5.6',
+			$genesis_version,
+			$GLOBALS['wp_version'],
+			PHP_VERSION
+		);
+	} elseif ( $compare_wp_version && $compare_php_version ) {
+		return sprintf(
+			// Translators: 1 is the required WordPress version, 2 is the required PHP version, 3 is the user's current WordPress version amd 4 is the user's current PHP version.
+			__( 'Prometheus 2 cannot be activated because it requires WordPress version %1$s and PHP version %2$s. The Genesis Framework (parent theme) has been activated instead. You are running WordPress version %3$s and PHP version %4$s. Please upgrade WordPress and PHP and try again.', 'prometheus2' ),
+			'4.9.6',
+			'5.6',
+			$GLOBALS['wp_version'],
+			PHP_VERSION
+		);
+	} elseif ( $compare_genesis_version && $compare_wp_version ) {
+		return sprintf(
+			// Translators: 1 is the required Genesis version, 2 is the required WordPress version, 3 is the user's current Genesis version and 4 is the user's current WordPress version.
+			__( 'Prometheus 2 was not activated because it requires Genesis version %1$s and WordPress version %2$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %3$s and WordPress version %4$s. Please upgrade Genesis and WordPress and try again.', 'prometheus2' ),
+			'2.6',
+			'4.9.6',
+			$genesis_version,
+			$GLOBALS['wp_version']
+		);
+	} elseif ( $compare_genesis_version && $compare_php_version ) {
+		return sprintf(
+			// Translators: 1 is the required Genesis version, 2 is the required PHP version, 3 is the user's current Genesis version and 4 is the user's current PHP version.
+			__( 'Prometheus 2 was not activated because it requires Genesis version %1$s and PHP version of %2$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %3$s and PHP version %4$s. Please upgrade Genesis and PHP and try again.', 'prometheus2' ),
+			'2.6',
+			'5.6',
+			$genesis_version,
+			PHP_VERSION
+		);
+	} elseif ( $compare_wp_version ) {
+		return sprintf(
+			// Translators: 1 is the required WordPress version and 2 is the user's current WordPress version.
+			__( 'Prometheus 2 was not activated because it requires WordPress version %1$s. The Genesis Framework (parent theme) has been activated instead. You are running WordPress version %2$s. Please upgrade WordPress and try again.', 'prometheus2' ),
+			'4.9.6',
+			$GLOBALS['wp_version']
+		);
+	} elseif ( $compare_php_version ) {
+		return sprintf(
+			// Translators: 1 is the required PHP version and 2 is the user's current PHP version.
+			__( 'Prometheus 2 was not activated because it requires PHP version %1$s. The Genesis Framework (parent theme) has been activated instead. You are running PHP version %2$s. Please upgrade PHP and try again.', 'prometheus2' ),
+			'5.6',
+			PHP_VERSION
+		);
+	} elseif ( $compare_genesis_version ) {
+		return sprintf(
+			// Translators: 1 is the required Genesis version and 2 is the user's current Genesis version.
+			__( 'Prometheus 2 was not activated because it requires Genesis version %1$s. The Genesis Framework (parent theme) has been activated instead. You are running Genesis version %2$s. Please upgrade Genesis and try again.', 'prometheus2' ),
+			'2.6',
+			$genesis_version
+		);
+	}
+	return '';
+}
diff --git a/package.json b/package.json
index 39da68f..09074a9 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
   },
   "homepage": "https://github.com/christophherr/prometheus#readme",
   "devDependencies": {
-    "ajv": "^6.5.0",
+    "ajv": "^6.5.4",
     "autoprefixer": "^9.2.1",
     "babel-core": "^6.26.0",
     "babel-preset-env": "^1.7.0",
@@ -67,8 +67,8 @@
     "prettier-eslint": "^8.2.1",
     "prettier-stylelint": "^0.4.2",
     "pump": "^3.0.0",
-    "sort-css-media-queries": "^1.3.4",
-    "stylelint": "^9.2.1",
+    "sort-css-media-queries": "^1.4.1",
+    "stylelint": "^9.6.0",
     "stylelint-config-wordpress": "^13.0.0",
     "stylelint-order": "^0.8.1"
   },
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index e69c170..d0cca88 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -61,6 +61,7 @@
 			<property name="prefixes" type="array">
 				<element value="CHILD_THEME"/>
 				<element value="CHILD_TEXT_DOMAIN"/>
+				<element value="prometheus_2"/>
 			</property>
 		</properties>
 	</rule>