diff --git a/sim/src/lib.rs b/sim/src/lib.rs
index 629b916..0fc9363 100644
--- a/sim/src/lib.rs
+++ b/sim/src/lib.rs
@@ -1196,6 +1196,13 @@
 }
 
 #[cfg(feature = "sig-ecdsa")]
+#[cfg(feature = "enc-kw")]
+fn make_tlv() -> TlvGen {
+    TlvGen::new_ecdsa_kw()
+}
+
+#[cfg(feature = "sig-ecdsa")]
+#[cfg(not(feature = "enc-kw"))]
 fn make_tlv() -> TlvGen {
     TlvGen::new_ecdsa()
 }
@@ -1213,6 +1220,7 @@
 }
 
 #[cfg(not(feature = "sig-rsa"))]
+#[cfg(not(feature = "sig-ecdsa"))]
 #[cfg(feature = "enc-kw")]
 fn make_tlv() -> TlvGen {
     TlvGen::new_enc_kw()
diff --git a/sim/src/tlv.rs b/sim/src/tlv.rs
index afc34aa..9aea50d 100644
--- a/sim/src/tlv.rs
+++ b/sim/src/tlv.rs
@@ -117,6 +117,16 @@
         }
     }
 
+    #[allow(dead_code)]
+    pub fn new_ecdsa_kw() -> TlvGen {
+        TlvGen {
+            flags: TlvFlags::ENCRYPTED as u32,
+            kinds: vec![TlvKinds::SHA256, TlvKinds::ECDSA256, TlvKinds::ENCKW128],
+            size: 4 + 32 + 4 + 32 + 4 + 72 + 4 + 24,
+            payload: vec![],
+        }
+    }
+
     /// Retrieve the header flags for this configuration.  This can be called at any time.
     pub fn get_flags(&self) -> u32 {
         self.flags