diff --git a/test/rustint/core_test.clj b/test/rustint/core_test.clj
index ccf6295..a0451c7 100644
--- a/test/rustint/core_test.clj
+++ b/test/rustint/core_test.clj
@@ -287,6 +287,16 @@
   )
 )
 
+(deftest convertir-formato-impresion-04
+  (testing "Test 04 convertir-formato-impresion"
+    (is (=
+         (convertir-formato-impresion '("Hola, mundo {}!" 2.0))
+         '("Hola, mundo %.0f!" 2.0)
+        )
+    )
+  )
+)
+
 (deftest get-rust-formatters-01
   (testing "Test 01 get-rust-formatters"
     (is (=