diff --git a/.changeset/polite-poems-fall.md b/.changeset/polite-poems-fall.md
new file mode 100644
index 00000000..0b2f1027
--- /dev/null
+++ b/.changeset/polite-poems-fall.md
@@ -0,0 +1,5 @@
+---
+"@opennextjs/cloudflare": patch
+---
+
+fix: type error during build
diff --git a/packages/cloudflare/src/api/overrides/incremental-cache/regional-cache.ts b/packages/cloudflare/src/api/overrides/incremental-cache/regional-cache.ts
index d2be28ab..84fef933 100644
--- a/packages/cloudflare/src/api/overrides/incremental-cache/regional-cache.ts
+++ b/packages/cloudflare/src/api/overrides/incremental-cache/regional-cache.ts
@@ -97,7 +97,8 @@ class RegionalCache implements IncrementalCache {
 	}
 
 	get #hasAutomaticCachePurging() {
-		const cdnInvalidation = globalThis.openNextConfig.default?.override?.cdnInvalidation;
+		// The `?` is required at `openNextConfig?` or the Open Next build fails because of a type error
+		const cdnInvalidation = globalThis.openNextConfig?.default?.override?.cdnInvalidation;
 
 		return cdnInvalidation !== undefined && cdnInvalidation !== "dummy";
 	}