diff --git a/NEWS.md b/NEWS.md
index 33b53c5de..15e079e39 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,8 @@
 # keras3 (development version)
 
+- TensorBoard is now declared explicitly as a Python dependency, restoring
+  `callback_tensorboard()` with TensorFlow 2.21.
+
 - On Linux, `use_backend("jax", gpu = TRUE)` no longer overrides
   `XLA_PYTHON_CLIENT_MEM_FRACTION`, preserving the JAX default or a
   user-provided value.
diff --git a/R/package.R b/R/package.R
index 77fcc782a..ef459bc49 100644
--- a/R/package.R
+++ b/R/package.R
@@ -70,7 +70,7 @@ keras <- NULL
     Sys.setenv(RETICULATE_PYTHON = keras_python)
 
   py_require(c(
-    "keras", "pydot", "scipy", "pandas", "Pillow", "ipython"
+    "keras", "tensorboard", "pydot", "scipy", "pandas", "Pillow", "ipython"
     #, "tensorflow_datasets"
   ))