diff --git a/embassy-stm32/src/exti.rs b/embassy-stm32/src/exti.rs
index d63af76b..5af51cd1 100644
--- a/embassy-stm32/src/exti.rs
+++ b/embassy-stm32/src/exti.rs
@@ -109,7 +109,10 @@ impl<'d, T: GpioPin> InputPin for ExtiInput<'d, T> {
 }
 
 impl<'d, T: GpioPin> WaitForRisingEdge for ExtiInput<'d, T> {
-    type Future<'a> = ExtiInputFuture<'a>;
+    type Future<'a>
+    where
+        Self: 'a,
+    = ExtiInputFuture<'a>;
 
     fn wait_for_rising_edge<'a>(&'a mut self) -> Self::Future<'a> {
         ExtiInputFuture::new(self.pin.pin.pin(), self.pin.pin.port(), true, false)
@@ -117,7 +120,10 @@ impl<'d, T: GpioPin> WaitForRisingEdge for ExtiInput<'d, T> {
 }
 
 impl<'d, T: GpioPin> WaitForFallingEdge for ExtiInput<'d, T> {
-    type Future<'a> = ExtiInputFuture<'a>;
+    type Future<'a>
+    where
+        Self: 'a,
+    = ExtiInputFuture<'a>;
 
     fn wait_for_falling_edge<'a>(&'a mut self) -> Self::Future<'a> {
         ExtiInputFuture::new(self.pin.pin.pin(), self.pin.pin.port(), false, true)
@@ -125,7 +131,10 @@ impl<'d, T: GpioPin> WaitForFallingEdge for ExtiInput<'d, T> {
 }
 
 impl<'d, T: GpioPin> WaitForAnyEdge for ExtiInput<'d, T> {
-    type Future<'a> = ExtiInputFuture<'a>;
+    type Future<'a>
+    where
+        Self: 'a,
+    = ExtiInputFuture<'a>;
 
     fn wait_for_any_edge<'a>(&'a mut self) -> Self::Future<'a> {
         ExtiInputFuture::new(self.pin.pin.pin(), self.pin.pin.port(), true, true)
diff --git a/embassy-traits/src/delay.rs b/embassy-traits/src/delay.rs
index caa0b100..c4ef155e 100644
--- a/embassy-traits/src/delay.rs
+++ b/embassy-traits/src/delay.rs
@@ -1,7 +1,9 @@
 use core::future::Future;
 
 pub trait Delay {
-    type DelayFuture<'a>: Future<Output = ()> + 'a;
+    type DelayFuture<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
     /// Future that completes after now + millis
     fn delay_ms(&mut self, millis: u64) -> Self::DelayFuture<'_>;
diff --git a/embassy-traits/src/gpio.rs b/embassy-traits/src/gpio.rs
index b8f31fc6..3752c8d6 100644
--- a/embassy-traits/src/gpio.rs
+++ b/embassy-traits/src/gpio.rs
@@ -2,7 +2,9 @@ use core::future::Future;
 
 /// Wait for a pin to become high.
 pub trait WaitForHigh {
-    type Future<'a>: Future<Output = ()> + 'a;
+    type Future<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
     /// Wait for a pin to become high.
     ///
@@ -13,7 +15,9 @@ pub trait WaitForHigh {
 
 /// Wait for a pin to become low.
 pub trait WaitForLow {
-    type Future<'a>: Future<Output = ()> + 'a;
+    type Future<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
     /// Wait for a pin to become low.
     ///
@@ -24,7 +28,9 @@ pub trait WaitForLow {
 
 /// Wait for a rising edge (transition from low to high)
 pub trait WaitForRisingEdge {
-    type Future<'a>: Future<Output = ()> + 'a;
+    type Future<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
     /// Wait for a rising edge (transition from low to high)
     fn wait_for_rising_edge(&mut self) -> Self::Future<'_>;
@@ -32,7 +38,9 @@ pub trait WaitForRisingEdge {
 
 /// Wait for a falling edge (transition from high to low)
 pub trait WaitForFallingEdge {
-    type Future<'a>: Future<Output = ()> + 'a;
+    type Future<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
     /// Wait for a falling edge (transition from high to low)
     fn wait_for_falling_edge(&'_ mut self) -> Self::Future<'_>;
@@ -40,7 +48,9 @@ pub trait WaitForFallingEdge {
 
 /// Wait for any edge (any transition, high to low or low to high)
 pub trait WaitForAnyEdge {
-    type Future<'a>: Future<Output = ()> + 'a;
+    type Future<'a>: Future<Output = ()> + 'a
+    where
+        Self: 'a;
 
     /// Wait for any edge (any transition, high to low or low to high)
     fn wait_for_any_edge(&mut self) -> Self::Future<'_>;
diff --git a/embassy-traits/src/spi.rs b/embassy-traits/src/spi.rs
index 04322ddd..14f79b05 100644
--- a/embassy-traits/src/spi.rs
+++ b/embassy-traits/src/spi.rs
@@ -27,7 +27,8 @@ pub trait Spi<Word> {
 pub trait FullDuplex<Word>: Spi<Word> + Write<Word> + Read<Word> {
     type WriteReadFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
     where
-        Self: 'a;
+        Self: 'a,
+        Word: 'a;
 
     /// The `read` array must be at least as long as the `write` array,
     /// but is guaranteed to only be filled with bytes equal to the
@@ -42,7 +43,8 @@ pub trait FullDuplex<Word>: Spi<Word> + Write<Word> + Read<Word> {
 pub trait Write<Word>: Spi<Word> {
     type WriteFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
     where
-        Self: 'a;
+        Self: 'a,
+        Word: 'a;
 
     fn write<'a>(&'a mut self, data: &'a [Word]) -> Self::WriteFuture<'a>;
 }
@@ -50,7 +52,8 @@ pub trait Write<Word>: Spi<Word> {
 pub trait Read<Word>: Write<Word> {
     type ReadFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
     where
-        Self: 'a;
+        Self: 'a,
+        Word: 'a;
 
     fn read<'a>(&'a mut self, data: &'a mut [Word]) -> Self::ReadFuture<'a>;
 }