diff --git a/compos/aidl/Android.bp b/compos/aidl/Android.bp
index 07bec09..4d36d3d 100644
--- a/compos/aidl/Android.bp
+++ b/compos/aidl/Android.bp
@@ -17,7 +17,7 @@
         },
         ndk: {
             apex_available: [
-                "com.android.virt",
+                "com.android.compos",
             ],
         },
     },
diff --git a/compos/aidl/com/android/compos/ICompOsKeyService.aidl b/compos/aidl/com/android/compos/ICompOsKeyService.aidl
index 2ddae58..a2ff917 100644
--- a/compos/aidl/com/android/compos/ICompOsKeyService.aidl
+++ b/compos/aidl/com/android/compos/ICompOsKeyService.aidl
@@ -37,4 +37,15 @@
      * @return whether the inputs are valid and correspond to each other.
      */
     boolean verifySigningKey(in byte[] keyBlob, in byte[] publicKey);
+
+    /**
+     * Use the supplied encrypted private key to sign some data.
+     *
+     * @param keyBlob The encrypted blob containing the private key, as returned by
+     *                generateSigningKey().
+     * @param data The data to be signed. (Large data sizes may cause failure.)
+     * @return the signature.
+     */
+    // STOPSHIP(b/193241041): We must not expose this from the PVM.
+    byte[] sign(in byte[] keyBlob, in byte[] data);
 }