diff --git a/services/root-keys/Cargo.toml b/services/root-keys/Cargo.toml
index 2e6d47a1d..72f4b0fb0 100644
--- a/services/root-keys/Cargo.toml
+++ b/services/root-keys/Cargo.toml
@@ -71,8 +71,9 @@ byteorder = "1.4.3" # used by keywrap
 hex = { version = "0.4.3", default-features = false, features = [] }
 
 [dependencies.curve25519-dalek]
-version = "=4.1.2"       # note this is patched to our fork in ./Cargo.toml
+version = "=4.1.2"                           # note this is patched to our fork in ./Cargo.toml
 default-features = false
+features = ["auto-release", "warn-fallback"]
 
 [dependencies.ed25519-dalek]
 version = "2.1.0"
diff --git a/services/root-keys/src/main.rs b/services/root-keys/src/main.rs
index 939e7c50d..933b48378 100644
--- a/services/root-keys/src/main.rs
+++ b/services/root-keys/src/main.rs
@@ -2382,9 +2382,6 @@ fn main() -> ! {
                 log::error!("couldn't convert opcode");
             }
         }
-        // de-allocate the engine at the end of root-keys, so other crates can use it.
-        #[cfg(target_os = "xous")]
-        curve25519_dalek::backend::serial::u32e::free_engine();
     }
     // clean up our program
     log::trace!("main loop exit, destroying servers");