diff --git a/google/cloud/firestore_v1/base_client.py b/google/cloud/firestore_v1/base_client.py
index 345e061428..a7c8a97274 100644
--- a/google/cloud/firestore_v1/base_client.py
+++ b/google/cloud/firestore_v1/base_client.py
@@ -131,7 +131,8 @@ def __init__(
             if credentials is None:
                 credentials = AnonymousCredentials()
             if project is None:
-                project = _DEFAULT_EMULATOR_PROJECT
+                # extract project from env var, or use system default
+                project = os.getenv("GCLOUD_PROJECT", _DEFAULT_EMULATOR_PROJECT)
 
         super(BaseClient, self).__init__(
             project=project,