diff --git a/caffe2/opt/onnxifi_transformer.cc b/caffe2/opt/onnxifi_transformer.cc
index 8089314c3100..2dd8c8d2d8b4 100644
--- a/caffe2/opt/onnxifi_transformer.cc
+++ b/caffe2/opt/onnxifi_transformer.cc
@@ -1195,11 +1195,11 @@ void OnnxifiTransformer::applyFilteringRules(
   blocklistCpuPartition(net, blocklisted_ops);
 }
 
-void OnnxifiTransformer::getBackendId() {
+std::vector<onnxBackendID> OnnxifiTransformer::getBackendId() {
   idx_ = 0;
 
   if (opts_.use_onnx) {
-    return;
+    return backend_ids_;
   }
   // Try to find a backend that support Caffe2 proto. Note that this is quite
   // opportunistic as we don't officially support Caffe2 proto.
@@ -1214,6 +1214,7 @@ void OnnxifiTransformer::getBackendId() {
       break;
     }
   }
+  return backend_ids_;
 }
 
 NetDef OnnxifiTransformer::TransformViaC2(
diff --git a/caffe2/opt/onnxifi_transformer.h b/caffe2/opt/onnxifi_transformer.h
index d88eb739750c..d1af1731013d 100644
--- a/caffe2/opt/onnxifi_transformer.h
+++ b/caffe2/opt/onnxifi_transformer.h
@@ -61,6 +61,17 @@ class TORCH_API OnnxifiTransformer final : public BackendTransformerBase {
       const ShapeInfoMap& shape_hints,
       const std::unordered_set<int>& blocklisted_ops) override;
 
+  // Query whether an operator is supported by passing C2 protobuf
+  bool supportOpC2(
+      const caffe2::OperatorDef& op,
+      const ShapeInfoMap& shape_hints,
+      const std::unordered_set<std::string>& weights,
+      const std::unordered_set<int>& blocklisted_ops,
+      onnxBackendID backend_id) const;
+
+  // Determine backend id
+  std::vector<onnxBackendID> getBackendId();
+
  private:
   // Since we create new tensors during the conversion process, we actually need
   // into inject them into the original workspace
@@ -114,14 +125,6 @@ class TORCH_API OnnxifiTransformer final : public BackendTransformerBase {
       ShapeInfoMap* shape_hints_max_bs,
       const std::unordered_map<int, ShapeInfoMap> &shape_hints_per_bs);
 
-  // Query whether an operator is supported by passing C2 protobuf
-  bool supportOpC2(
-      const caffe2::OperatorDef& op,
-      const ShapeInfoMap& shape_hints,
-      const std::unordered_set<std::string>& weights,
-      const std::unordered_set<int>& blocklisted_ops,
-      onnxBackendID backend_id) const;
-
   // Query whether an operator is supported by passing ONNX protobuf
   bool supportOpOnnx(
       const caffe2::OperatorDef& op,
@@ -152,9 +155,6 @@ class TORCH_API OnnxifiTransformer final : public BackendTransformerBase {
       const std::unordered_set<std::string>& weights,
       std::unordered_set<int>* blocklisted_ops) const;
 
-  // Determine backend id
-  void getBackendId();
-
   // Extract partition info from the original net
   void extractPartitionInfo(const NetDef& net);