diff --git a/src/Device/Context.cpp b/src/Device/Context.cpp
index 0d88fce..cb8131f 100644
--- a/src/Device/Context.cpp
+++ b/src/Device/Context.cpp
@@ -350,7 +350,6 @@
 	}
 }
 
-// TODO(b/137740918): Optimize instancing to use a single draw call.
 void Inputs::advanceInstanceAttributes(bool dynamicInstanceStride)
 {
 	for(uint32_t i = 0; i < vk::MAX_VERTEX_INPUT_BINDINGS; i++)
diff --git a/src/System/Debug.hpp b/src/System/Debug.hpp
index 10457b3..f3d3932 100644
--- a/src/System/Debug.hpp
+++ b/src/System/Debug.hpp
@@ -159,4 +159,14 @@
 		} while(0)
 #endif
 
+// A macro to indicate unoptimized code paths.
+#define UNOPTIMIZED(message, ...)                                                            \
+	do                                                                                       \
+	{                                                                                        \
+		if(false)                                                                            \
+		{                                                                                    \
+			sw::warn("%s:%d UNOPTIMIZED: " message "\n", __FILE__, __LINE__, ##__VA_ARGS__); \
+		}                                                                                    \
+	} while(0)
+
 #endif  // Debug_hpp
diff --git a/src/Vulkan/VkCommandBuffer.cpp b/src/Vulkan/VkCommandBuffer.cpp
index f333d1f..3bfe933 100644
--- a/src/Vulkan/VkCommandBuffer.cpp
+++ b/src/Vulkan/VkCommandBuffer.cpp
@@ -957,7 +957,11 @@
 				}
 			}
 
-			inputs.advanceInstanceAttributes(hasDynamicVertexStride);
+			if(instanceCount > 1)
+			{
+				UNOPTIMIZED("Optimize instancing to use a single draw call.");  // TODO(b/137740918)
+				inputs.advanceInstanceAttributes(hasDynamicVertexStride);
+			}
 		}
 	}
 };