diff --git a/README.md b/README.md
index 3f7b4bd..82f7846 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,11 @@
 # harp-python
 
+> [!WARNING]
+> **This package is deprecated and will no longer receive updates.**
+>
+> Please migrate to the new [`harp-python`](https://github.com/harp-tech/python) package, which supersedes this one with an improved API and continued support.
+> A [migration guide](https://harp-tech.org/python/articles/harp-python-migration/) is available to help you transition.
+
 A low-level interface to data collected with the [Harp binary protocol](https://harp-tech.org/protocol/BinaryProtocol-8bit.html).
 
 ## How to install
diff --git a/harp/__init__.py b/harp/__init__.py
index ba6211c..ef7732a 100644
--- a/harp/__init__.py
+++ b/harp/__init__.py
@@ -1,3 +1,12 @@
+import warnings
+
+warnings.warn(
+    "The 'harp-python' package is deprecated and will no longer receive updates. "
+    "Please migrate to the new 'harp-data' package: pip install harp-data",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
 from harp.io import REFERENCE_EPOCH, MessageType, read, to_buffer, to_file
 from harp.reader import create_reader
 from harp.schema import read_schema