diff --git a/.changeset/flat-papayas-invite.md b/.changeset/flat-papayas-invite.md
new file mode 100644
index 000000000000..c8b1193d7662
--- /dev/null
+++ b/.changeset/flat-papayas-invite.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Allow astro to be installed underneath a folder with leading slashes
diff --git a/packages/astro/src/content/vite-plugin-content-virtual-mod.ts b/packages/astro/src/content/vite-plugin-content-virtual-mod.ts
index ecda537e2094..6ab920c4d84e 100644
--- a/packages/astro/src/content/vite-plugin-content-virtual-mod.ts
+++ b/packages/astro/src/content/vite-plugin-content-virtual-mod.ts
@@ -21,6 +21,7 @@ import {
 	type ContentLookupMap,
 	type ContentPaths,
 } from './utils.js';
+import { appendForwardSlash } from '../core/path.js';
 
 interface AstroContentVirtualModPluginParams {
 	settings: AstroSettings;
@@ -209,5 +210,6 @@ const UnexpectedLookupMapError = new AstroError({
 
 function globWithUnderscoresIgnored(relContentDir: string, exts: string[]): string[] {
 	const extGlob = getExtGlob(exts);
-	return [`${relContentDir}/**/*${extGlob}`, `!**/_*/**${extGlob}`, `!**/_*${extGlob}`];
+	const contentDir = appendForwardSlash(relContentDir);
+	return [`${contentDir}**/*${extGlob}`, `!${contentDir}_*/**${extGlob}`, `!${contentDir}_*${extGlob}`];
 }