2 files changed, 5 insertions, 1 deletions

diff --git a/embassy-embedded-hal/Cargo.toml b/embassy-embedded-hal/Cargo.toml
index d2606d264..455786be9 100644
--- a/embassy-embedded-hal/Cargo.toml
+++ b/embassy-embedded-hal/Cargo.toml
@@ -15,4 +15,6 @@ embedded-hal-1 = { package = "embedded-hal", version = "1.0.0-alpha.8" }
 embedded-hal-async = { version = "0.1.0-alpha.1", optional = true }
 embedded-storage = "0.3.0"
 embedded-storage-async = { version = "0.3.0", optional = true }
-nb = "1.0.0"
\ No newline at end of file
+nb = "1.0.0"
+
+defmt = { version = "0.3", optional = true }
diff --git a/embassy-embedded-hal/src/shared_bus/mod.rs b/embassy-embedded-hal/src/shared_bus/mod.rs
index 76ee413d9..617d921e9 100644
--- a/embassy-embedded-hal/src/shared_bus/mod.rs
+++ b/embassy-embedded-hal/src/shared_bus/mod.rs
@@ -10,6 +10,7 @@ pub mod blocking;
 
 /// Error returned by I2C device implementations in this crate.
 #[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum I2cDeviceError<BUS> {
     /// An operation on the inner I2C bus failed.
     I2c(BUS),
@@ -28,6 +29,7 @@ where
 
 /// Error returned by SPI device implementations in this crate.
 #[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum SpiDeviceError<BUS, CS> {
     /// An operation on the inner SPI bus failed.
     Spi(BUS),