diff --git a/AK/Base64.h b/AK/Base64.h
index 9493e634e56..52396fe0578 100644
--- a/AK/Base64.h
+++ b/AK/Base64.h
@@ -13,14 +13,13 @@
 
 namespace AK {
 
-size_t calculate_base64_decoded_length(StringView);
+[[nodiscard]] size_t calculate_base64_decoded_length(StringView);
 
-size_t calculate_base64_encoded_length(ReadonlyBytes);
+[[nodiscard]] size_t calculate_base64_encoded_length(ReadonlyBytes);
 
-ErrorOr<ByteBuffer> decode_base64(StringView);
-
-String encode_base64(ReadonlyBytes);
+[[nodiscard]] ErrorOr<ByteBuffer> decode_base64(StringView);
 
+[[nodiscard]] String encode_base64(ReadonlyBytes);
 }
 
 using AK::decode_base64;