diff --git a/AGENTS.md b/AGENTS.md
index 6682f71a4..04364cb39 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -342,6 +342,11 @@
   comments, but do not disrespect her.
 - Warning and info messages should be short and actionable. Remove noisy or
   misleading messages rather than adding more logging.
+- Setting `is_deprecated` (or similar flags like `is_experimental`) as a class
+  attribute on a V3 (`io.ComfyNode`) node is not enough by itself: it must also
+  be passed into the `io.Schema(...)` returned by `define_schema()` (e.g.
+  `is_deprecated=cls.is_deprecated`). `/object_info` and the frontend's
+  deprecated-node filtering read the schema, not the class attribute.
 - Documentation and README edits should be concise, factual, and tied to the
   changed behavior.
 
diff --git a/comfy_extras/nodes_dataset.py b/comfy_extras/nodes_dataset.py
index 71e5ee368..7e6901676 100644
--- a/comfy_extras/nodes_dataset.py
+++ b/comfy_extras/nodes_dataset.py
@@ -701,6 +701,7 @@ class ImageProcessingNode(io.ComfyNode):
                     tooltip="Processed images",
                 )
             ],
+            is_deprecated=cls.is_deprecated,
         )
 
     @classmethod
@@ -873,6 +874,7 @@ class TextProcessingNode(io.ComfyNode):
                     tooltip="Processed texts",
                 )
             ],
+            is_deprecated=cls.is_deprecated,
         )
 
     @classmethod
diff --git a/tests-unit/comfy_extras_test/nodes_dataset_test.py b/tests-unit/comfy_extras_test/nodes_dataset_test.py
new file mode 100644
index 000000000..695a12217
--- /dev/null
+++ b/tests-unit/comfy_extras_test/nodes_dataset_test.py
@@ -0,0 +1,47 @@
+from comfy_extras import nodes_dataset
+
+
+def _all_node_classes():
+    """Every node class registered by the dataset extension."""
+    return [
+        cls for cls in vars(nodes_dataset).values()
+        if isinstance(cls, type) and issubclass(cls, nodes_dataset.io.ComfyNode)
+    ]
+
+
+def test_is_deprecated_propagates_to_schema():
+    """A node's class-level is_deprecated flag must reach define_schema()'s
+    io.Schema, since /object_info (and the frontend's deprecated-node filter)
+    reads the schema, not the class attribute. See PR that fixed nodes like
+    ReplaceTextNode reporting deprecated: false despite is_deprecated = True."""
+    for node_cls in _all_node_classes():
+        if getattr(node_cls, "node_id", "") is None:
+            continue  # abstract base class (ImageProcessingNode/TextProcessingNode), not a real node
+        if not hasattr(node_cls, "is_deprecated"):
+            continue  # node builds its Schema with is_deprecated inline, nothing to compare
+        class_flag = bool(node_cls.is_deprecated)
+        schema_flag = bool(node_cls.define_schema().is_deprecated)
+        assert schema_flag == class_flag, (
+            f"{node_cls.__name__}: class is_deprecated={class_flag} but "
+            f"define_schema().is_deprecated={schema_flag}"
+        )
+
+
+def test_known_deprecated_nodes_report_deprecated_in_schema():
+    deprecated_nodes = [
+        nodes_dataset.ResizeImagesByShorterEdgeNode,
+        nodes_dataset.ResizeImagesByLongerEdgeNode,
+        nodes_dataset.MergeImageListsNode,
+        nodes_dataset.TextToLowercaseNode,
+        nodes_dataset.TextToUppercaseNode,
+        nodes_dataset.AddTextPrefixNode,
+        nodes_dataset.AddTextSuffixNode,
+        nodes_dataset.ReplaceTextNode,
+        nodes_dataset.StripWhitespaceNode,
+        nodes_dataset.MergeTextListsNode,
+        nodes_dataset.SaveImageDataSetToFolderNode,
+    ]
+    for node_cls in deprecated_nodes:
+        assert node_cls.define_schema().is_deprecated is True, (
+            f"{node_cls.__name__} should report deprecated: true in its schema"
+        )