diff --git a/libwvdrmengine/apex/prebuilt/Android.bp b/libwvdrmengine/apex/prebuilt/Android.bp
index bb2aaef3..7aff21f3 100644
--- a/libwvdrmengine/apex/prebuilt/Android.bp
+++ b/libwvdrmengine/apex/prebuilt/Android.bp
@@ -25,27 +25,39 @@ package {
     default_applicable_licenses: ["vendor_widevine_license"],
 }
 
-apex_set {
+soong_config_module_type {
+    name: "widevine_apex_set",
+    module_type: "apex_set",
+    config_namespace: "widevine",
+    bool_variables: ["source_build"],
+    properties: ["prefer"],
+}
+
+widevine_apex_set {
     name: "com.google.android.widevine.nonupdatable",
     apex_name: "com.google.android.widevine",
     owner: "google",
     set: "com.google.android.widevine.nonupdatable.apks",
     vendor: true,
-    use_source_config_var: {
-        config_namespace: "widevine",
-        var_name: "source_build",
+    prefer: true,
+    soong_config_variables: {
+        source_build: {
+            prefer: false,
+        },
     },
 }
 
-apex_set {
+widevine_apex_set {
     name: "com.google.android.widevine.lazy",
     apex_name: "com.google.android.widevine.lazy",
     owner: "google",
     set: "com.google.android.widevine.lazy.apks",
     vendor: true,
-    use_source_config_var: {
-        config_namespace: "widevine",
-        var_name: "source_build",
+    prefer: true,
+    soong_config_variables: {
+        source_build: {
+            prefer: false,
+        },
     },
 }
 
diff --git a/libwvdrmengine/oemcrypto/test/oec_session_util.cpp b/libwvdrmengine/oemcrypto/test/oec_session_util.cpp
index 36db07a6..4ffb714e 100644
--- a/libwvdrmengine/oemcrypto/test/oec_session_util.cpp
+++ b/libwvdrmengine/oemcrypto/test/oec_session_util.cpp
@@ -1414,6 +1414,7 @@ void EntitledMessage::LoadCasKeys(bool load_even, bool load_odd,
     even_key.content_key_data_iv = entitled_key_array_[0].content_key_data_iv;
     even_key.content_key_data = entitled_key_array_[0].content_key_data;
     even_key.content_iv = entitled_key_array_[0].content_iv;
+    even_key.cipher_mode = OEMCrypto_CipherMode_CBC;
   }
   if (has_odd) {
     odd_key.entitlement_key_id = entitled_key_array_[1].entitlement_key_id;
@@ -1421,6 +1422,7 @@ void EntitledMessage::LoadCasKeys(bool load_even, bool load_odd,
     odd_key.content_key_data_iv = entitled_key_array_[1].content_key_data_iv;
     odd_key.content_key_data = entitled_key_array_[1].content_key_data;
     odd_key.content_iv = entitled_key_array_[1].content_iv;
+    odd_key.cipher_mode = OEMCrypto_CipherMode_CBC;
   }
 
   OEMCryptoResult sts = OEMCrypto_LoadCasECMKeys(