diff --git a/studio/backend/utils/transformers_version.py b/studio/backend/utils/transformers_version.py
index 7924f78396..35c79ba9d2 100644
--- a/studio/backend/utils/transformers_version.py
+++ b/studio/backend/utils/transformers_version.py
@@ -89,7 +89,8 @@ _config_needs_550_cache: dict[str, bool] = {}
 TRANSFORMERS_550_VERSION = "5.5.0"
 TRANSFORMERS_530_VERSION = "5.3.0"
 TRANSFORMERS_DEFAULT_VERSION = "4.57.6"
-# Backwards-compat alias used by other modules
+# Backwards-compat alias — points to 5.5.0 (the highest 5.x tier).
+# Consumers should prefer TRANSFORMERS_530_VERSION / TRANSFORMERS_550_VERSION.
 TRANSFORMERS_5_VERSION = TRANSFORMERS_550_VERSION
 
 # Pre-installed directories — created by setup.sh / setup.ps1
diff --git a/studio/setup.sh b/studio/setup.sh
index 2b2c14e9b4..9d047b7d65 100755
--- a/studio/setup.sh
+++ b/studio/setup.sh
@@ -558,6 +558,7 @@ if [ "$_SKIP_PYTHON_DEPS" = false ]; then
     # Clean up legacy single .venv_t5 directory
     [ -d "$STUDIO_HOME/.venv_t5" ] && rm -rf "$STUDIO_HOME/.venv_t5"
 
+    [ -d "$VENV_T5_530_DIR" ] && rm -rf "$VENV_T5_530_DIR"
     mkdir -p "$VENV_T5_530_DIR"
     run_quiet "install transformers 5.3.0" fast_install --target "$VENV_T5_530_DIR" --no-deps "transformers==5.3.0"
     run_quiet "install huggingface_hub for t5_530" fast_install --target "$VENV_T5_530_DIR" --no-deps "huggingface_hub==1.8.0"
@@ -565,6 +566,7 @@ if [ "$_SKIP_PYTHON_DEPS" = false ]; then
     run_quiet "install tiktoken for t5_530" fast_install --target "$VENV_T5_530_DIR" "tiktoken"
     step "transformers" "5.3.0 pre-installed"
 
+    [ -d "$VENV_T5_550_DIR" ] && rm -rf "$VENV_T5_550_DIR"
     mkdir -p "$VENV_T5_550_DIR"
     run_quiet "install transformers 5.5.0" fast_install --target "$VENV_T5_550_DIR" --no-deps "transformers==5.5.0"
     run_quiet "install huggingface_hub for t5_550" fast_install --target "$VENV_T5_550_DIR" --no-deps "huggingface_hub==1.8.0"