diff --git a/src/types.ts b/src/types.ts
index 5104fe71fd..4a93eed9aa 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -50,3 +50,5 @@ export interface OpenPGPSignaturesData {
   };
   fingerprint: string;
 }
+
+export type OS = 'linux' | 'darwin' | 'windows' | 'mobile';