diff --git a/Cargo.toml b/Cargo.toml
index 2eb20f9..29ba431 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,11 +11,11 @@ keywords = ["embedded", "buffer", "embedded-io", "read", "write"]
 exclude = [".github"]
 
 [dependencies]
-embedded-io = { version = "0.6" }
-embedded-io-async = { version = "0.6" }
+embedded-io = { version = "0.7" }
+embedded-io-async = { version = "0.7" }
 
 [dev-dependencies]
-embedded-io-async = { version = "0.6", features = ["std"] }
-embedded-io-adapters = { version = "0.6", features = ["std"] }
+embedded-io-async = { version = "0.7", features = ["std"] }
+embedded-io-adapters = { version = "0.7", features = ["std"] }
 tokio = { version = "1", features = ["macros", "rt"] }
 tokio-test = "0.4"
diff --git a/src/asynch/write.rs b/src/asynch/write.rs
index f54c093..ef6fdf6 100644
--- a/src/asynch/write.rs
+++ b/src/asynch/write.rs
@@ -213,6 +213,14 @@ mod tests {
     #[derive(Debug)]
     struct UnstableError;
 
+    impl core::fmt::Display for UnstableError {
+        fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+            write!(f, "UnstableError")
+        }
+    }
+
+    impl std::error::Error for UnstableError {}
+
     impl Error for UnstableError {
         fn kind(&self) -> ErrorKind {
             ErrorKind::Other
@@ -234,6 +242,10 @@ mod tests {
                 Err(UnstableError)
             }
         }
+
+        async fn flush(&mut self) -> Result<(), Self::Error> {
+            Ok(())
+        }
     }
 
     #[tokio::test]