diff --git a/mla/Cargo.toml b/mla/Cargo.toml
index b714f8bb..947f4fb6 100644
--- a/mla/Cargo.toml
+++ b/mla/Cargo.toml
@@ -39,7 +39,7 @@ aes-gcm = "0"
 aead = "0"
 criterion = "0.3"
 curve25519-parser = { path = "../curve25519-parser" }
-hex = "0.3" # from 0.4, hex comes with dependencies
+hex = "0.4" # from 0.4, hex comes with dependencies
 
 [[bench]]
 name = "bench_archive"
diff --git a/mlar/Cargo.toml b/mlar/Cargo.toml
index 604e3896..007f81d1 100644
--- a/mlar/Cargo.toml
+++ b/mlar/Cargo.toml
@@ -15,7 +15,7 @@ curve25519-parser = { path = "../curve25519-parser" }
 rand = "0.7"
 x25519-dalek = "0"
 humansize = "1"
-hex = "0.3" # from 0.4, hex comes with dependencies
+hex = "0.4" # from 0.4, hex comes with dependencies
 # Could be made optional / feature to enable (for binary size)
 tar = "0.4"
 rand_chacha = "0.2"