diff --git a/libs/vertexai/langchain_google_vertexai/_utils.py b/libs/vertexai/langchain_google_vertexai/_utils.py
index 4799a4ab..8562ca14 100644
--- a/libs/vertexai/langchain_google_vertexai/_utils.py
+++ b/libs/vertexai/langchain_google_vertexai/_utils.py
@@ -138,7 +138,7 @@ def _missing_(cls, value: Any) -> "GoogleModelFamily":
             return GoogleModelFamily.CODEY
         if "medlm-medium@latest" in model_name:
             return GoogleModelFamily.GEMINI
-        if "bison" in model_name or "medlm" in model_name:
+        if "bison" in model_name or "medlm" in model_name or "unicorn" in model_name:
             return GoogleModelFamily.PALM
         return GoogleModelFamily.GEMINI