diff --git a/requirements.txt b/requirements.txt
index 36fd376..f2d1d31 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1015,9 +1015,9 @@ msgpack==1.0.7 \
     --hash=sha256:f9a7c509542db4eceed3dcf21ee5267ab565a83555c9b88a8109dcecc4709002 \
     --hash=sha256:ff1d0899f104f3921d94579a5638847f783c9b04f2d5f229392ca77fba5b82fc
     # via flax
-nltk==3.8.1 \
-    --hash=sha256:1834da3d0682cba4f2cede2f9aad6b0fafb6461ba451db0efb6f9c39798d64d3 \
-    --hash=sha256:fd5c9109f976fa86bcadba8f91e47f5e9293bd034474752e92a520f81c93dda5
+nltk==3.9 \
+    --hash=sha256:d17863e861bb33ac617893329d71d06a3dfb7e3eb9ee0b8105281c53944a45a1 \
+    --hash=sha256:e98acac454407fa38b76cccb29208d377731cf7fab68f323754a3681f104531f
     # via
     #   rouge-score
     #   t5
@@ -2064,5 +2064,6 @@ zipp==3.17.0 \
     # via etils
 
 # WARNING: The following packages were not pinned, but pip requires them to be
-# pinned when the requirements file includes hashes. Consider using the --allow-unsafe flag.
+# pinned when the requirements file includes hashes and the requirement is not
+# satisfied by a package already installed. Consider using the --allow-unsafe flag.
 # setuptools