diff --git a/.changeset/polite-donkeys-reflect.md b/.changeset/polite-donkeys-reflect.md
new file mode 100644
index 0000000000..7af6e055b6
--- /dev/null
+++ b/.changeset/polite-donkeys-reflect.md
@@ -0,0 +1,5 @@
+---
+"@electric-sql/debug-toolbar": patch
+---
+
+Guard against adding toolbar to DOM twice
diff --git a/components/toolbar/src/index.tsx b/components/toolbar/src/index.tsx
index 4b3cbd42c9..38d25e3867 100644
--- a/components/toolbar/src/index.tsx
+++ b/components/toolbar/src/index.tsx
@@ -103,6 +103,13 @@ export function clientApi(registry: GlobalRegistry | Registry) {
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export function addToolbar(electric: ElectricClient<any>) {
+  if (document.getElementById(TOOLBAR_CONTAINER_ID)) {
+    console.warn(
+      '[@electric-sql/debug-toolbar] Toolbar has already been added.',
+    )
+    return
+  }
+
   const toolbarApi = clientApi(electric.registry)
 
   const containerDiv = document.createElement('div')