diff --git a/packages/ui-patterns/src/UnexpectedErrorPage.tsx b/packages/ui-patterns/src/UnexpectedErrorPage.tsx
index 3f1f3fd..156cd17 100644
--- a/packages/ui-patterns/src/UnexpectedErrorPage.tsx
+++ b/packages/ui-patterns/src/UnexpectedErrorPage.tsx
@@ -21,8 +21,11 @@ import { ErrorPage } from "./ErrorPage";
 import { uiPatternsMessage } from "./messages";
 
 export interface UnexpectedErrorPageProps {
-  /** Where "raising a support request" links to. */
-  supportUrl: string;
+  /**
+   * Where "raising a support request" links to. Omit it and the page does
+   * not mention support, for deployments without a support site.
+   */
+  supportUrl?: string;
   /**
    * Identifies the error report, typically the Sentry event id, so a support
    * request quoting it can be matched to the report. Omit when the error was
@@ -57,18 +60,20 @@ export const UnexpectedErrorPage = ({
       />
     }
   >
-    <Text>
-      <FormattedMessage
-        {...uiPatternsMessage("ui-patterns.support-request")}
-        values={{
-          link: (chunks: ReactNode) => (
-            <ExternalLink href={supportUrl} color="brand.600">
-              {chunks}
-            </ExternalLink>
-          ),
-        }}
-      />
-    </Text>
+    {supportUrl && (
+      <Text>
+        <FormattedMessage
+          {...uiPatternsMessage("ui-patterns.support-request")}
+          values={{
+            link: (chunks: ReactNode) => (
+              <ExternalLink href={supportUrl} color="brand.600">
+                {chunks}
+              </ExternalLink>
+            ),
+          }}
+        />
+      </Text>
+    )}
     {reference && <ErrorReference reference={reference} />}
     {children}
     <Box mt={2}>
diff --git a/packages/ui-patterns/stories/UnexpectedErrorPage.stories.tsx b/packages/ui-patterns/stories/UnexpectedErrorPage.stories.tsx
index 742f53c..5bbd446 100644
--- a/packages/ui-patterns/stories/UnexpectedErrorPage.stories.tsx
+++ b/packages/ui-patterns/stories/UnexpectedErrorPage.stories.tsx
@@ -44,3 +44,11 @@ export const WithRecoveryAction: Story = {
     ),
   },
 };
+
+/** A deployment with no support site of its own. */
+export const WithoutSupportSite: Story = {
+  args: {
+    supportUrl: undefined,
+    reference: "5f1e7a2c9b3d4e6f8a0b1c2d3e4f5a6b",
+  },
+};
diff --git a/packages/ui-patterns/tests/ErrorPages.test.tsx b/packages/ui-patterns/tests/ErrorPages.test.tsx
index 801a37b..d361f5d 100644
--- a/packages/ui-patterns/tests/ErrorPages.test.tsx
+++ b/packages/ui-patterns/tests/ErrorPages.test.tsx
@@ -49,6 +49,13 @@ describe("UnexpectedErrorPage", () => {
     expect(onReload).toHaveBeenCalledOnce();
   });
 
+  it("omits the support text when there is no support site", () => {
+    render(<UnexpectedErrorPage reference="abc123" />, { wrapper: Providers });
+    expect(screen.queryByRole("link")).toBeNull();
+    expect(screen.queryByText(/support request/)).toBeNull();
+    expect(screen.getByText(/Error reference/)).toBeDefined();
+  });
+
   it("focuses the heading on mount", () => {
     render(<UnexpectedErrorPage supportUrl={supportUrl} />, {
       wrapper: Providers,