diff --git a/src/argon2.ts b/src/argon2.ts
index 27852bb..88375a3 100644
--- a/src/argon2.ts
+++ b/src/argon2.ts
@@ -4,7 +4,7 @@ import { blake2b } from './blake2b.js';
 import u64 from './_u64.js';
 
 // Experimental Argon2 RFC 9106 implementation. It may be removed at any time.
-enum Types {
+const enum Types {
   Argond2d = 0,
   Argon2i = 1,
   Argon2id = 2,
diff --git a/src/blake3.ts b/src/blake3.ts
index 873d0da..ce2a88b 100644
--- a/src/blake3.ts
+++ b/src/blake3.ts
@@ -5,7 +5,7 @@ import { compress, IV } from './blake2s.js';
 import { Input, u8, u32, toBytes, HashXOF, wrapXOFConstructorWithOpts } from './utils.js';
 
 // Flag bitset
-enum Flags {
+const enum Flags {
   CHUNK_START = 1 << 0,
   CHUNK_END = 1 << 1,
   PARENT = 1 << 2,