diff --git a/third_party/onnx b/third_party/onnx
index 20835f8..9f70c11 160000
--- a/third_party/onnx
+++ b/third_party/onnx
@@ -1 +1 @@
-Subproject commit 20835f8f238a232de2f1540fc109de62759e2495
+Subproject commit 9f70c118910f7174f65dac84c90d46d608d9cfd2
diff --git a/tools/onnx2bnn/OnnxConverter.cpp b/tools/onnx2bnn/OnnxConverter.cpp
index 5da62e3..9794f43 100644
--- a/tools/onnx2bnn/OnnxConverter.cpp
+++ b/tools/onnx2bnn/OnnxConverter.cpp
@@ -191,10 +191,11 @@ std::vector<std::string> OnnxConverter::Convert(
     // Please check out "dabnn_*" pases in
     // https://github.com/daquexian/onnx/blob/optimizer_for_bnn/onnx/optimizer/passes
     // for details.
-    vector<string> optimizers{"eliminate_nop_pad",
-                              "extract_constant_to_initializer",
-                              "dabnn_convert_gemm_with_reshape_or_flatten_to_conv_and_reshape",
-                              "dabnn_bconv_strict"};
+    vector<string> optimizers{
+        "eliminate_nop_pad", "extract_constant_to_initializer",
+        "dabnn_eliminate_dropout",
+        "dabnn_convert_gemm_with_reshape_or_flatten_to_conv_and_reshape",
+        "dabnn_bconv_strict"};
     if (level == Level::kModerate || level == Level::kAggressive) {
         optimizers.push_back("dabnn_bconv_moderate");
     }
@@ -231,13 +232,23 @@ std::vector<std::string> OnnxConverter::Convert(
         }
 
         Shape shape;
-        for (const auto &dim : input.type().tensor_type().shape().dim()) {
+        const auto &dims = input.type().tensor_type().shape().dim();
+        FORZ(i, dims.size()) {
+            if (i == 0) {
+                // We ignore the value of batch dimension since dabnn doesn't
+                // support batch input
+                shape.push_back(1);
+                continue;
+            }
+            const auto &dim = dims.Get(i);
             if (dim.value_case() ==
                 ONNX_NAMESPACE::TensorShapeProto_Dimension::kDimValue) {
                 shape.push_back(static_cast<uint32_t>(dim.dim_value()));
             } else {
                 throw std::invalid_argument(
-                    "The input of graph doesn't have dim_value");
+                    "Dim " + std::to_string(i) + " of input \"" + input.name() +
+                    "\" is not static, please re-export your ONNX model with "
+                    "static input shape");
             }
         }
         Shape nhwc_shape{shape[0], shape[2], shape[3], shape[1]};
@@ -248,17 +259,16 @@ std::vector<std::string> OnnxConverter::Convert(
     }
 
     vector<string> binary_conv_outputs;
-    vector<string> skipped_act;
     bool has_reshape = false;
     for (const auto &node : model_proto_.graph().node()) {
-        if (has_reshape) {
-            throw std::invalid_argument(
-                "Reshape can only be the last layer for now");
-        }
         NodeAttrHelper helper(node);
         const auto &op = node.op_type();
         VLOG(5) << "Node " << node.name();
         if (op == "Conv") {
+            if (has_reshape) {
+                throw std::invalid_argument("Reshape before " + op +
+                                            " is not supported");
+            }
             VLOG(5) << "Start converting Conv";
             auto strides = helper.get("strides", vector<int>{1, 1});
             auto pads = helper.get("pads", vector<int>{0, 0, 0, 0});
@@ -308,6 +318,10 @@ std::vector<std::string> OnnxConverter::Convert(
             VLOG(5) << "Converting Conv completed";
         } else if (op == "AveragePool" || op == "MaxPool" ||
                    op == "GlobalAveragePool" || op == "GlobalMaxPool") {
+            if (has_reshape) {
+                throw std::invalid_argument("Reshape before " + op +
+                                            " is not supported");
+            }
             VLOG(5) << "Start converting Pool";
             auto input_name = m(node.input(0));
             auto output_name = m(node.output(0));
@@ -396,6 +410,10 @@ std::vector<std::string> OnnxConverter::Convert(
             layers_.push_back(layer);
             VLOG(5) << "Converting Relu completed";
         } else if (op == "Add") {
+            if (has_reshape) {
+                throw std::invalid_argument("Reshape before " + op +
+                                            " is not supported");
+            }
             VLOG(5) << "Start converting Add";
             auto input1_name = m(node.input(0));
             auto input2_name = m(node.input(1));
@@ -409,6 +427,9 @@ std::vector<std::string> OnnxConverter::Convert(
             layers_.push_back(layer);
             VLOG(5) << "Converting Add completed";
         } else if (op == "Gemm") {
+            if (has_reshape) {
+                has_reshape = false;
+            }
             VLOG(5) << "Start converting Gemm";
             auto transA = helper.get("transA", 0);
             auto transB = helper.get("transB", 0);
@@ -467,6 +488,10 @@ std::vector<std::string> OnnxConverter::Convert(
             layers_.push_back(layer);
             VLOG(5) << "Converting Softmax completed";
         } else if (op == "Concat") {
+            if (has_reshape) {
+                throw std::invalid_argument("Reshape before " + op +
+                                            " is not supported");
+            }
             VLOG(5) << "Start converting Concat";
             vector<std::string> concat_inputs_str;
             for (const auto &onnx_input : node.input()) {
@@ -486,11 +511,6 @@ std::vector<std::string> OnnxConverter::Convert(
                                      0, 0, 0, 0, 0, 0, param);
             layers_.push_back(layer);
             VLOG(5) << "Converting Concat completed";
-        } else if (op == "Dropout") {
-            VLOG(5) << "Start converting Dropout";
-            // Dropout does nothing, so the output is the same as the input
-            name_map_[node.output(0)] = m(node.input(0));
-            VLOG(5) << "Converting Dropout completed";
         } else if (op == "Reshape") {
             VLOG(5) << "Start converting Reshape";
             has_reshape = true;