diff --git a/src/class-tiny-apache-rewrite.php b/src/class-tiny-apache-rewrite.php
index e6944d70..31b5aa12 100644
--- a/src/class-tiny-apache-rewrite.php
+++ b/src/class-tiny-apache-rewrite.php
@@ -24,7 +24,7 @@
  * - inserting/removing rules from htaccess
  *
  * We are only updating rules when:
- * - updating the option convert_format
+ * - adding or updating the option convert_format
  * - uninstalling the plug-in
  */
 class Tiny_Apache_Rewrite extends Tiny_WP_Base {
@@ -36,6 +36,19 @@ class Tiny_Apache_Rewrite extends Tiny_WP_Base {
 	 */
 	const MARKER = 'tiny-compress-images';
 
+	/**
+	 * Installs the htaccess rules when the option convert_format is saved
+	 * for the first time, which adds it instead of updating it.
+	 * hooked into `add_option_tinypng_convert_format`
+	 *
+	 * @param string $option
+	 * @param mixed  $value
+	 * @return void
+	 */
+	public static function toggle_rules_for_new_option( $option, $value ) {
+		self::toggle_rules( null, $value, $option );
+	}
+
 	/**
 	 * Installs or uninstalls the htaccess rules
 	 * hooked into `update_option_tinypng_convert_format`
diff --git a/src/class-tiny-conversion.php b/src/class-tiny-conversion.php
index 9934f1ad..b59b5765 100644
--- a/src/class-tiny-conversion.php
+++ b/src/class-tiny-conversion.php
@@ -37,18 +37,20 @@ public function __construct( $settings ) {
 	}
 
 	/**
-	 * will check if conversion is enabled,
-	 * if true:
+	 * will add hooks to toggle rules when the conversion settings are saved,
+	 * also while conversion is off, because saving is what turns it on.
+	 * will check if conversion is enabled, if true:
 	 * - will enable the delivery method
-	 * - will add hook to toggle rules
 	 *
 	 * hooked into `init`
 	 */
 	public function init() {
-		if ( ! $this->settings->get_conversion_enabled() ) {
-			return;
-		}
-
+		add_action(
+			'add_option_tinypng_convert_format',
+			'Tiny_Apache_Rewrite::toggle_rules_for_new_option',
+			20,
+			2
+		);
 		add_action(
 			'update_option_tinypng_convert_format',
 			'Tiny_Apache_Rewrite::toggle_rules',
@@ -56,6 +58,10 @@ public function init() {
 			3
 		);
 
+		if ( ! $this->settings->get_conversion_enabled() ) {
+			return;
+		}
+
 		$delivery_method = $this->settings->get_conversion_delivery_method();
 
 		$this->init_image_delivery( $delivery_method );
diff --git a/test/unit/Tiny_Apache_Rewrite_Test.php b/test/unit/Tiny_Apache_Rewrite_Test.php
index 1174cab2..78009335 100644
--- a/test/unit/Tiny_Apache_Rewrite_Test.php
+++ b/test/unit/Tiny_Apache_Rewrite_Test.php
@@ -23,6 +23,62 @@ function test_plugin_init_will_add_hook()
         WordPressStubs::assertHook('update_option_tinypng_convert_format', 'Tiny_Apache_Rewrite::toggle_rules');
     }
 
+    /**
+     * The request that turns conversion on still has it off during init,
+     * so the hook must be there to install the rules.
+     */
+    function test_plugin_init_will_add_hook_when_conversion_is_off()
+    {
+        $GLOBALS['is_apache'] = false;
+
+        $mock_settings = $this->createMock(Tiny_Settings::class);
+        $mock_settings->method('get_conversion_enabled')->willReturn(false);
+
+        new Tiny_Conversion($mock_settings);
+
+        $this->wp->init();
+
+        WordPressStubs::assertHook('update_option_tinypng_convert_format', 'Tiny_Apache_Rewrite::toggle_rules');
+    }
+
+    /**
+     * The first save of convert_format adds the option instead of updating it.
+     */
+    function test_plugin_init_will_add_hook_for_new_option()
+    {
+        $GLOBALS['is_apache'] = false;
+
+        $mock_settings = $this->createMock(Tiny_Settings::class);
+        $mock_settings->method('get_conversion_enabled')->willReturn(false);
+
+        new Tiny_Conversion($mock_settings);
+
+        $this->wp->init();
+
+        WordPressStubs::assertHook('add_option_tinypng_convert_format', 'Tiny_Apache_Rewrite::toggle_rules_for_new_option');
+    }
+
+    /**
+     * Saving convert_format for the first time with htaccess delivery
+     * inserts the rules in the upload directory.
+     */
+    function test_toggle_rules_for_new_option_installs_upload_dir_htaccess()
+    {
+        $upload_dir = $this->vfs->url() . '/wp-content/uploads';
+        $htaccess_file = $upload_dir . '/.htaccess';
+
+        if (!is_dir($upload_dir)) {
+            mkdir($upload_dir, 0755, true);
+        }
+
+        Tiny_Apache_Rewrite::toggle_rules_for_new_option(
+            'tinypng_convert_format',
+            array('convert' => 'on', 'delivery_method' => 'htaccess')
+        );
+
+        $this->assertStringContainsString('tiny-compress-images', file_get_contents($htaccess_file));
+    }
+
     /**
      * uninstall_rules removes htaccess rules from upload directory.
      * - creates a htaccess file in uploads directory