diff --git a/samples/03_model_render/model_render.cpp b/samples/03_model_render/model_render.cpp
index dd26d96..230cf4c 100644
--- a/samples/03_model_render/model_render.cpp
+++ b/samples/03_model_render/model_render.cpp
@@ -298,12 +298,15 @@ main(int, char **)
 
         for (auto &prim : model.m_MeshPrimitives)
         {
-            cmd.pushConstants(pipeline.m_Layout, vk::ShaderStageFlagBits::eAll, pcbOffset, sizeof prim.m_MaterialIdx,
+            u32 innerPcbOffset = pcbOffset;
+            cmd.pushConstants(pipeline.m_Layout, vk::ShaderStageFlagBits::eAll, innerPcbOffset,
+                              sizeof prim.m_MaterialIdx,
                               &prim.m_MaterialIdx);
-            pcbOffset += sizeof prim.m_MaterialIdx;
-            cmd.pushConstants(pipeline.m_Layout, vk::ShaderStageFlagBits::eAll, pcbOffset, sizeof prim.m_TransformIdx,
+            innerPcbOffset += sizeof prim.m_MaterialIdx;
+            cmd.pushConstants(pipeline.m_Layout, vk::ShaderStageFlagBits::eAll, innerPcbOffset,
+                              sizeof prim.m_TransformIdx,
                               &prim.m_TransformIdx);
-            pcbOffset += sizeof prim.m_TransformIdx;
+            innerPcbOffset += sizeof prim.m_TransformIdx;
             cmd.drawIndexed(prim.m_IndexCount, 1, prim.m_FirstIndex, Cast<i32>(prim.m_VertexOffset), 0);
         }