diff --git a/.changeset/modern-jokes-attack.md b/.changeset/modern-jokes-attack.md
new file mode 100644
index 0000000000..3cb3143f05
--- /dev/null
+++ b/.changeset/modern-jokes-attack.md
@@ -0,0 +1,5 @@
+---
+'@backstage/core-components': patch
+---
+
+Made AlertDisplay not crash on undefined messages
diff --git a/packages/core-components/src/components/AlertDisplay/AlertDisplay.tsx b/packages/core-components/src/components/AlertDisplay/AlertDisplay.tsx
index 3af261da23..c1f8f51db0 100644
--- a/packages/core-components/src/components/AlertDisplay/AlertDisplay.tsx
+++ b/packages/core-components/src/components/AlertDisplay/AlertDisplay.tsx
@@ -83,7 +83,7 @@ export function AlertDisplay(props: AlertDisplayProps) {
         severity={firstMessage.severity}
       >
         <span>
-          {firstMessage.message.toString()}
+          {String(firstMessage.message)}
           {messages.length > 1 && (
             <em>{` (${messages.length - 1} older ${pluralize(
               'message',