diff --git a/src/builder/frontend_dialect_transformer.cpp b/src/builder/frontend_dialect_transformer.cpp
index 43f8aa9..040aa89 100644
--- a/src/builder/frontend_dialect_transformer.cpp
+++ b/src/builder/frontend_dialect_transformer.cpp
@@ -611,7 +611,7 @@ private:
    * a specialized function is used
    */
   void ImportNodeConv(
-      onnx::NodeProto node, int nIn, int nOut,
+      onnx::NodeProto node, int nOut,
       std::initializer_list<std::tuple<std::string, std::string, std::string>>
           attrs) {
     // Conv has attribute dilations, kernel_shape, pads, the default value of
@@ -624,12 +624,12 @@ private:
     // similar situation for pads, strides in AveragePool
     // axes of ReduceSum,  pads, strides, dilations and kernel_shape of MaxPool
     // TODO: fix this after type inference
+    int nOps = node.input().size();
 
-    if (node.input().size() == 1) {
-      ImportNodeOneOut<mlir::ONNXConv1Op>(node, nIn, nOut, attrs);
-    } else {
-      ImportNodeOneOut<mlir::ONNXConv3Op>(node, nIn, nOut, attrs);
-    }
+    if (nOps == 2)
+      ImportNodeOneOut<mlir::ONNXConvNoBiasOp>(node, nOps, nOut, attrs);
+    else
+      ImportNodeOneOut<mlir::ONNXConvOp>(node, nOps, nOut, attrs);
   }
 
   void ImportNode(onnx::NodeProto node) {
diff --git a/src/builder/op_build_table.inc b/src/builder/op_build_table.inc
index b9e5720..78c4f98 100644
--- a/src/builder/op_build_table.inc
+++ b/src/builder/op_build_table.inc
@@ -87,7 +87,7 @@
          {"value","", ""}
       });
     }else if (OpName == "Conv") {
-       ImportNodeConv(node, 3, 1, {
+       ImportNodeConv(node, 1, {
          {"auto_pad","str","NOTSET"}
         ,{"dilations","", ""}
         ,{"group","int", "1"}
diff --git a/src/dialect/onnx/onnx.td b/src/dialect/onnx/onnx.td
index 87901ce..734668f 100644
--- a/src/dialect/onnx/onnx.td
+++ b/src/dialect/onnx/onnx.td
@@ -92,26 +92,15 @@ def ONNXFullGemmOp: ONNX_Op<"FullGemm",
   let results = (outs AnyTensor);
 }
 
-def ONNXConv1Op:ONNX_Op<"Conv1", 
+def ONNXConvNoBiasOp:ONNX_Op<"ConvNoBias",
     [NoSideEffect]> {
-  let summary = "ONNX Conv operation";
+  let summary = "ONNX Conv operation with no Bias operand.";
   let description = [{
     "The convolution operator consumes an input tensor and a filter, and"
     "computes the output."
   }];
-  let arguments = (ins AnyTensor:$X);
-  let results = (outs AnyTensor);
-}
-
-def ONNXConv3Op:ONNX_Op<"Conv3", 
-    [NoSideEffect]> {
-  let summary = "ONNX Conv operation";
-  let description = [{
-    "The convolution operator consumes an input tensor and a filter, and"
-    "computes the output."
-  }];
-  let arguments = (ins AnyTensor:$X, AnyTensor:$W, AnyTensor:$B);
-  let results = (outs AnyTensor);
+  let arguments = (ins AnyTypeOf<[AnyMemRef, AnyTensor]>:$X, AnyTypeOf<[AnyMemRef, AnyTensor]>:$W);
+  let results = (outs AnyTypeOf<[AnyMemRef, AnyTensor]>);
 }
 
 #endif // ONNX_OPS
diff --git a/src/dialect/onnx/onnxop.inc b/src/dialect/onnx/onnxop.inc
index 3ec669a..16ad979 100644
--- a/src/dialect/onnx/onnxop.inc
+++ b/src/dialect/onnx/onnxop.inc
@@ -315,14 +315,14 @@ def ONNXConstantOfShapeOp:ONNX_Op<"ConstantOfShape",
   let results = (outs AnyTypeOf<[AnyMemRef, AnyTensor]>);
 }
 
-def ONNXConvOp:ONNX_Op<"Conv", 
+def ONNXConvOp:ONNX_Op<"Conv",
     [NoSideEffect]> {
   let summary = "ONNX Conv operation";
   let description = [{
     "The convolution operator consumes an input tensor and a filter, and"
     "computes the output."
   }];
-  let arguments = (ins AnyTypeOf<[AnyMemRef, AnyTensor]>:$X, AnyTypeOf<[AnyMemRef, AnyTensor]>:$W, Variadic<AnyTypeOf<[AnyMemRef, AnyTensor]>>:$B);
+  let arguments = (ins AnyTypeOf<[AnyMemRef, AnyTensor]>:$X, AnyTypeOf<[AnyMemRef, AnyTensor]>:$W, AnyTypeOf<[AnyMemRef, AnyTensor]>:$B);
   let results = (outs AnyTypeOf<[AnyMemRef, AnyTensor]>);
 }