diff --git a/types/mongodb/index.d.ts b/types/mongodb/index.d.ts
index 3de97daf60..ef7b7768d8 100644
--- a/types/mongodb/index.d.ts
+++ b/types/mongodb/index.d.ts
@@ -1786,7 +1786,7 @@ export interface CollationDocument {
     locale: string;
     strength?: number;
     caseLevel?: boolean;
-    caseFirst?: boolean;
+    caseFirst?: string;
     numericOrdering?: boolean;
     alternate?: string;
     maxVariable?: string;