diff --git a/src/wp-admin/includes/class-wp-press-this.php b/src/wp-admin/includes/class-wp-press-this.php
index 4a2bde8922..9313f71f9c 100644
--- a/src/wp-admin/includes/class-wp-press-this.php
+++ b/src/wp-admin/includes/class-wp-press-this.php
@@ -1167,6 +1167,24 @@ class WP_Press_This {
 		return $content;
 	}
 
+	/**
+	 * Sets the user agent used for Press This HTTP requests.
+	 *
+	 * @since 4.3.0
+	 * @access public
+	 *
+	 * @global string $wp_version
+	 *
+	 * @return string User agent.
+	 */
+	public function ua_string() {
+		global $wp_version;
+
+		$user_agent = 'Press This (WordPress/' . $wp_version . '); ' . get_bloginfo( 'url' );
+
+		return $user_agent;
+	}
+
 	/**
 	 * Serves the app's base HTML, which in turns calls the load script.
 	 *
@@ -1180,6 +1198,9 @@ class WP_Press_This {
 	public function html() {
 		global $wp_locale, $wp_version;
 
+		// Set explicit user-agent for the $data outbound HTTP requests.
+		add_filter( 'http_headers_useragent', array( $this, 'ua_string' ) );
+
 		// Get data, new (POST) and old (GET).
 		$data = $this->merge_or_fetch_data();