diff --git a/docs/src/main/tut/usage.md b/docs/src/main/tut/usage.md
index 852eae96..ff60f672 100644
--- a/docs/src/main/tut/usage.md
+++ b/docs/src/main/tut/usage.md
@@ -216,7 +216,7 @@ class PgSpec extends AnyFlatSpec with TestContainerForAll {
   )
 
   "PostgreSQL container" should "be started" in {
-    withContainers { pgContainer =>
+    withContainers { case pgContainer: PostgreSQLContainer =>
       Class.forName(pgContainer.driverClassName)
       val connection = DriverManager.getConnection(pgContainer.jdbcUrl, pgContainer.username, pgContainer.password)
       assert(!connection.isClosed())