diff --git a/backend/python/kokoro/install.sh b/backend/python/kokoro/install.sh
index d3b88ea68..3e1ab8606 100755
--- a/backend/python/kokoro/install.sh
+++ b/backend/python/kokoro/install.sh
@@ -21,3 +21,8 @@ if [ "x${BUILD_PROFILE}" == "xl4t12" ]; then
 fi
 
 installRequirements
+
+# spaCy is a dependency of misaki (used by kokoro for English phonemization).
+# Pre-download the model here because at runtime the portable Python environment
+# has no pip/uv, so spacy's auto-download would fail.
+python -m spacy download en_core_web_sm