diff --git a/embassy-stm32/src/flash/f4.rs b/embassy-stm32/src/flash/f4.rs
index 3c8f81eb..9698bcd5 100644
--- a/embassy-stm32/src/flash/f4.rs
+++ b/embassy-stm32/src/flash/f4.rs
@@ -139,6 +139,7 @@ mod alt_regions {
                 }
             }
 
+            #[cfg(all(feature = "nightly"))]
             impl embedded_storage_async::nor_flash::ReadNorFlash for $type_name<'_> {
                 const READ_SIZE: usize = READ_SIZE;
 
@@ -151,6 +152,7 @@ mod alt_regions {
                 }
             }
 
+            #[cfg(all(feature = "nightly"))]
             impl embedded_storage_async::nor_flash::NorFlash for $type_name<'_> {
                 const WRITE_SIZE: usize = $region.write_size as usize;
                 const ERASE_SIZE: usize = $region.erase_size as usize;