diff --git a/Cargo.toml b/Cargo.toml
index cf74268..eb602bd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,7 +28,7 @@ httpdate = { version = "1", optional = true }
 mime = { version = "0.3.4", optional = true }
 fastrand = { version = "2.0", optional = true }
 quoted_printable = { version = "0.5", optional = true }
-base64 = { version = "0.21", optional = true }
+base64 = { version = "0.22", optional = true }
 email-encoding = { version = "0.2", optional = true }
 
 # file transport