diff --git a/component-runtime-beam/src/main/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformer.java b/component-runtime-beam/src/main/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformer.java
index a5ef97656c32b..62b00345386ff 100644
--- a/component-runtime-beam/src/main/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformer.java
+++ b/component-runtime-beam/src/main/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformer.java
@@ -260,8 +260,6 @@ private static BiConsumer<OutputStream, Object> doCreateSerializer() {
                         writeClass.invoke(oos, obj, false);
                     } else if (ObjectStreamClass.class.isInstance(obj)) {
                         writeClassDesc.invoke(oos, obj, false);
-                    } else if (String.class.isInstance(obj)) {
-                        writeClassDesc.invoke(oos, obj, false);
                     } else if (obj instanceof String) {
                         writeString.invoke(oos, obj, false);
                     } else if (obj.getClass().isArray()) {
diff --git a/component-runtime-beam/src/test/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformerTest.java b/component-runtime-beam/src/test/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformerTest.java
index f0e238d6aa467..181f85678d62e 100644
--- a/component-runtime-beam/src/test/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformerTest.java
+++ b/component-runtime-beam/src/test/java/org/talend/sdk/component/runtime/beam/transformer/BeamIOTransformerTest.java
@@ -120,6 +120,18 @@ void coder() {
         });
     }
 
+    @Test
+    void bypassReplaceSerializerHandlesString() {
+        // Ensures the custom serializer used by SerializationWrapper writes top-level String
+        // values via writeString instead of falling into the wrong writeClassDesc branch.
+        scenario((transformer, loader) -> {
+            final BeamIOTransformer.SerializationWrapper wrapper =
+                    (BeamIOTransformer.SerializationWrapper) BeamIOTransformer.SerializationWrapper
+                            .replace("hello", "test");
+            assertEquals("hello", wrapper.readResolve());
+        });
+    }
+
     @Test
     void coderSerialization() {
         scenario((transformer, loader) -> {