diff --git a/requirements-ci.txt b/requirements-ci.txt
index 6c74f688c..ebea04615 100644
--- a/requirements-ci.txt
+++ b/requirements-ci.txt
@@ -18,6 +18,7 @@ git+https://github.com/lhotse-speech/lhotse
 kaldilm==1.11
 kaldialign==0.7.1
 num2words
+pypinyin==0.50.0
 sentencepiece==0.1.96
 tensorboard==2.8.0
 typeguard==2.13.3
diff --git a/requirements.txt b/requirements.txt
index a1a46ae64..dec20c6e4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,9 +4,10 @@ kaldialign
 num2words
 kaldi-decoder
 sentencepiece>=0.1.96
+pypinyin==0.50.0
 tensorboard
 typeguard
 dill
 black==22.3.0
 onnx==1.15.0
-onnxruntime==1.16.3
\ No newline at end of file
+onnxruntime==1.16.3