diff --git a/.changeset/giant-ways-switch.md b/.changeset/giant-ways-switch.md
new file mode 100644
index 00000000..4c2be345
--- /dev/null
+++ b/.changeset/giant-ways-switch.md
@@ -0,0 +1,5 @@
+---
+"@sebspark/spanner-mock": patch
+---
+
+Spanner creates one unique client per projectId