diff --git a/Cargo.toml b/Cargo.toml
index d70176a..d90d4b0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,6 +3,10 @@ name = "soft-serial"
 version = "0.1.0"
 edition = "2021"
 
+[dependencies.ufmt]
+version = "*"
+optional = true
+
 [dependencies.ring-buffer]
 git = "https://gitea.doryan04.ru/doryan/ring-buffer"
 optional = true
@@ -17,6 +21,7 @@ git = "https://gitea.doryan04.ru/TheEmbeddedRust/static-pins"
 [features]
 sparkfun-promicro = ["arduino-hal/sparkfun-promicro", "static-pins/sparkfun-promicro"]
 ring-buf = ["dep:ring-buffer"]
+ufmt = ["dep:ufmt"]
 
 [dependencies.avr-device]
 version = "0.5.4"