diff --git a/demo/Diffusion/models.py b/demo/Diffusion/models.py
index ed921784..8664b7b7 100644
--- a/demo/Diffusion/models.py
+++ b/demo/Diffusion/models.py
@@ -345,9 +345,9 @@ def insert_seq2spatial_plugin(self):
                 inputTensor = biasNode.inputs[inputIndex]
                 residualInput = residualNode.inputs[1]
                 outputTensor = transposeNode.outputs[0]
+                outputShapeTensor = transposeNode.i().i().i(1).i(1).i(1).i().inputs[0]
                 seqLen2SpatialNode = gs.Node("SeqLen2Spatial", "AddAddSeqLen2Spatial-" + str(nSeqLen2SpatialPlugin),
-                    attrs=OrderedDict([("height", outputTensor.shape[2]), ("width", outputTensor.shape[3])]),
-                    inputs=[inputTensor, biasInput, residualInput], outputs=[outputTensor])
+                    inputs=[inputTensor, biasInput, residualInput, outputShapeTensor], outputs=[outputTensor])
                 self.graph.nodes.append(seqLen2SpatialNode)
                 biasNode.inputs.clear()
                 transposeNode.outputs.clear()
@@ -841,8 +841,7 @@ def optimize(self, onnx_graph, minimal_optimization=False):
         # Insert Split+GeLU Plugin
         bSplitGeLUPlugin = True
         # Replace BiasAdd+ResidualAdd+SeqLen2Spatial with plugin
-        # TODO - support dynamic shapes in plugin
-        bSeqLen2SpatialPlugin = False
+        bSeqLen2SpatialPlugin = True
 
         opt = Optimizer(onnx_graph, verbose=self.verbose)
         opt.info('UNet: original')
diff --git a/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.cpp b/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.cpp
index a25a8c08..23b0a384 100644
--- a/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.cpp
+++ b/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.cpp
@@ -28,29 +28,17 @@ namespace
 {
 static std::string const kSEQLEN2SPATIAL_PLUGIN_NAME{"SeqLen2Spatial"};
 static std::string const kSEQLEN2SPATIAL_PLUGIN_VERSION{"1"};
-size_t constexpr kSERIALIZATION_SIZE{2 * sizeof(int32_t)};
+size_t constexpr kSERIALIZATION_SIZE{0};
 } // namespace
 
-SeqLen2SpatialPlugin::SeqLen2SpatialPlugin(std::string const& name, int32_t height, int32_t width)
+SeqLen2SpatialPlugin::SeqLen2SpatialPlugin(std::string const& name)
     : mName(name)
-    , mHeight(height)
-    , mWidth(width)
 {
 }
 
 SeqLen2SpatialPlugin::SeqLen2SpatialPlugin(std::string const& name, void const* buffer, size_t length)
     : mName(name)
 {
-    PLUGIN_VALIDATE(buffer != nullptr);
-    PLUGIN_VALIDATE(length == kSERIALIZATION_SIZE);
-
-    auto const* d = static_cast<char const*>(buffer);
-    auto const* a = d;
-
-    mHeight = read<int32_t>(d);
-    mWidth = read<int32_t>(d);
-
-    PLUGIN_VALIDATE(d == a + length);
 }
 
 IPluginV2DynamicExt* SeqLen2SpatialPlugin::clone() const noexcept
@@ -93,25 +81,7 @@ DataType SeqLen2SpatialPlugin::getOutputDataType(
 DimsExprs SeqLen2SpatialPlugin::getOutputDimensions(
     int32_t outputIndex, DimsExprs const* inputs, int32_t nbInputs, IExprBuilder& exprBuilder) noexcept
 {
-    DimsExprs ret{};
-    try
-    {
-        PLUGIN_VALIDATE(inputs != nullptr);
-        PLUGIN_VALIDATE(nbInputs > 0);
-        DimsExprs inputDims = inputs[0];
-        DimsExprs outputDims;
-        outputDims.nbDims = 4;
-        outputDims.d[0] = inputDims.d[0];
-        outputDims.d[1] = inputDims.d[2];
-        outputDims.d[2] = exprBuilder.constant(mHeight);
-        outputDims.d[3] = exprBuilder.constant(mWidth);
-        ret = outputDims;
-    }
-    catch (std::exception const& e)
-    {
-        caughtError(e);
-    }
-    return ret;
+    return inputs[3];
 }
 
 bool SeqLen2SpatialPlugin::supportsFormatCombination(
@@ -122,7 +92,7 @@ bool SeqLen2SpatialPlugin::supportsFormatCombination(
         PLUGIN_VALIDATE(inOut != nullptr);
         PLUGIN_VALIDATE(nbInputs + nbOutputs > 0);
         PLUGIN_VALIDATE(pos < nbInputs + nbOutputs);
-        PLUGIN_VALIDATE(pos >= 0 && pos <= 3);
+        PLUGIN_VALIDATE(pos >= 0 && pos <= 4);
 
         if (pos == 0)
         {
@@ -136,6 +106,11 @@ bool SeqLen2SpatialPlugin::supportsFormatCombination(
         }
 
         if (pos == 3)
+        {
+            return inOut[pos].type == DataType::kFLOAT && inOut[pos].format == TensorFormat::kLINEAR;
+        }
+
+        if (pos == 4)
         {
             return inOut[pos].type == inOut[0].type
                 && ((inOut[pos].type == DataType::kFLOAT && inOut[pos].format == TensorFormat::kHWC)
@@ -204,19 +179,6 @@ size_t SeqLen2SpatialPlugin::getSerializationSize() const noexcept
 
 void SeqLen2SpatialPlugin::serialize(void* buffer) const noexcept
 {
-    try
-    {
-        PLUGIN_VALIDATE(buffer != nullptr);
-        auto* d = static_cast<char*>(buffer);
-        auto* a = d;
-        write(d, mHeight); // int32_t
-        write(d, mWidth);  // int32_t
-        PLUGIN_VALIDATE(d == a + getSerializationSize());
-    }
-    catch (std::exception const& e)
-    {
-        caughtError(e);
-    }
 }
 
 void SeqLen2SpatialPlugin::setPluginNamespace(char const* pluginNamespace) noexcept
@@ -245,8 +207,6 @@ std::vector<PluginField> SeqLen2SpatialPluginCreator::mPluginAttributes;
 SeqLen2SpatialPluginCreator::SeqLen2SpatialPluginCreator()
 {
     mPluginAttributes.clear();
-    mPluginAttributes.emplace_back(PluginField("height", nullptr, PluginFieldType::kINT32, 1));
-    mPluginAttributes.emplace_back(PluginField("width", nullptr, PluginFieldType::kINT32, 1));
     mFC.nbFields = mPluginAttributes.size();
     mFC.fields = mPluginAttributes.data();
 }
@@ -257,28 +217,7 @@ IPluginV2* SeqLen2SpatialPluginCreator::createPlugin(char const* name, PluginFie
 {
     try
     {
-        PLUGIN_VALIDATE(fc != nullptr);
-        PluginField const* fields = fc->fields;
-
-        // default values
-        int32_t mHeight{0};
-        int32_t mWidth{0};
-
-        for (int32_t i = 0; i < fc->nbFields; ++i)
-        {
-            char const* attrName = fields[i].name;
-            if (!strcmp(attrName, "height"))
-            {
-                PLUGIN_VALIDATE(fields[i].type == PluginFieldType::kINT32);
-                mHeight = static_cast<int32_t>(*(static_cast<int32_t const*>(fields[i].data)));
-            }
-            else if (!strcmp(attrName, "width"))
-            {
-                PLUGIN_VALIDATE(fields[i].type == PluginFieldType::kINT32);
-                mWidth = static_cast<int32_t>(*(static_cast<int32_t const*>(fields[i].data)));
-            }
-        }
-        return new SeqLen2SpatialPlugin(name, mHeight, mWidth);
+        return new SeqLen2SpatialPlugin(name);
     }
     catch (std::exception const& e)
     {
@@ -292,7 +231,6 @@ IPluginV2* SeqLen2SpatialPluginCreator::deserializePlugin(
 {
     try
     {
-        PLUGIN_VALIDATE(serialData != nullptr);
         return new SeqLen2SpatialPlugin(name, serialData, serialLength);
     }
     catch (std::exception const& e)
diff --git a/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.h b/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.h
index 955ff2fd..612d231c 100644
--- a/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.h
+++ b/plugin/seqLen2SpatialPlugin/seqLen2SpatialPlugin.h
@@ -34,7 +34,7 @@ class SeqLen2SpatialPlugin : public IPluginV2DynamicExt
 {
 public:
     SeqLen2SpatialPlugin() = delete;
-    SeqLen2SpatialPlugin(std::string const& name, int32_t height, int32_t width);
+    SeqLen2SpatialPlugin(std::string const& name);
     SeqLen2SpatialPlugin(std::string const& name, void const* buffer, size_t length);
     ~SeqLen2SpatialPlugin() override = default;
 
@@ -74,8 +74,6 @@ class SeqLen2SpatialPlugin : public IPluginV2DynamicExt
 private:
     std::string mName;
     std::string mNameSpace;
-    int32_t mHeight{};
-    int32_t mWidth{};
 };
 
 class SeqLen2SpatialPluginCreator : public nvinfer1::pluginInternal::BaseCreator