diff --git a/core/libs/prx/libSceAgcDriver/Execution/src/Driver/Draw/Draw.cpp b/core/libs/prx/libSceAgcDriver/Execution/src/Driver/Draw/Draw.cpp
index 5634d788a..97c2905da 100644
--- a/core/libs/prx/libSceAgcDriver/Execution/src/Driver/Draw/Draw.cpp
+++ b/core/libs/prx/libSceAgcDriver/Execution/src/Driver/Draw/Draw.cpp
@@ -91,7 +91,7 @@ DrawVerdict Driver::draw(QueueState& queue, std::span<const std::uint32_t> packe
         if (!graphics.stages.mesh) return;
         auto& words = programs.front().userData;
         require(programs.front().firstUserSgpr == 0 && words.size() >= ShaderRecompiler::MeshIndexBufferUserWord + 4, "mesh program lacks the hidden user words");
-        const auto descriptor = Graphics::MeshIndexBufferDescriptor(parameters, programs.front().binary.codeAddress);
+        const auto descriptor = Graphics::MeshIndexBufferDescriptor(parameters);
         std::copy(descriptor.begin(), descriptor.end(), words.begin() + ShaderRecompiler::MeshIndexBufferUserWord);
     };
     if (!drawParameters.indirect) setMeshIndexBuffer(drawParameters);
diff --git a/core/libs/prx/libSceAgcDriver/Graphics/include/Draw.hpp b/core/libs/prx/libSceAgcDriver/Graphics/include/Draw.hpp
index e8fc9a7c2..078e05bb2 100644
--- a/core/libs/prx/libSceAgcDriver/Graphics/include/Draw.hpp
+++ b/core/libs/prx/libSceAgcDriver/Graphics/include/Draw.hpp
@@ -28,7 +28,7 @@ struct DrawInputCopy {
 DrawInputCopy CopyDrawInput(const Context& context, Recorder* recorder, std::uint64_t address, std::size_t bytes, std::size_t alignment, Recorder::SnapshotUse use);
 void KeepDrawInput(Recorder* recorder, std::uint64_t address, const DrawInputCopy& copy, Recorder::SnapshotUse use, std::uint32_t derived);
 
-std::array<std::uint32_t, 4> MeshIndexBufferDescriptor(const Pm4::DrawParameters& draw, std::uint64_t unreadAddress);
+std::array<std::uint32_t, 4> MeshIndexBufferDescriptor(const Pm4::DrawParameters& draw);
 
 struct MeshArguments {
     std::uint32_t groups;
diff --git a/core/libs/prx/libSceAgcDriver/Graphics/src/Draw.cpp b/core/libs/prx/libSceAgcDriver/Graphics/src/Draw.cpp
index cd8095a8f..2ddc3a9a2 100644
--- a/core/libs/prx/libSceAgcDriver/Graphics/src/Draw.cpp
+++ b/core/libs/prx/libSceAgcDriver/Graphics/src/Draw.cpp
@@ -601,11 +601,12 @@ void CheckBufferAliases(std::span<const CompiledShader> shaders, const ColorTarg
 
 }
 
-std::array<std::uint32_t, 4> MeshIndexBufferDescriptor(const Pm4::DrawParameters& draw, std::uint64_t unreadAddress) {
-    const auto address = draw.indexed ? draw.indexAddress : unreadAddress;
-    const auto bytes = draw.indexed ? (static_cast<std::uint64_t>(draw.indexCount) * draw.indexSize + 3u) & ~std::uint64_t{3} : 4u;
-    Require(address != 0 && bytes != 0 && bytes <= 0xffffffffu && (address >> 48u) == 0, "invalid mesh index buffer range");
+std::array<std::uint32_t, 4> MeshIndexBufferDescriptor(const Pm4::DrawParameters& draw) {
     constexpr std::uint32_t RawWord3 = 0x31016facu;
+    if (!draw.indexed) return {0u, 0u, 0u, RawWord3};
+    const auto address = draw.indexAddress;
+    const auto bytes = (static_cast<std::uint64_t>(draw.indexCount) * draw.indexSize + 3u) & ~std::uint64_t{3};
+    Require(address != 0 && bytes != 0 && bytes <= 0xffffffffu && (address >> 48u) == 0, "invalid mesh index buffer range");
     return {static_cast<std::uint32_t>(address), static_cast<std::uint32_t>(address >> 32u) & 0xffffu, static_cast<std::uint32_t>(bytes), RawWord3};
 }
 
diff --git a/core/libs/prx/libSceAgcDriver/tests/Graphics.cpp b/core/libs/prx/libSceAgcDriver/tests/Graphics.cpp
index 2d45534e2..c70920772 100644
--- a/core/libs/prx/libSceAgcDriver/tests/Graphics.cpp
+++ b/core/libs/prx/libSceAgcDriver/tests/Graphics.cpp
@@ -1977,6 +1977,16 @@ bool recompilesDebugBranch(std::uint32_t opcode) {
     return !ShaderRecompiler::Recompile(request).spirv.Words().empty();
 }
 
+void meshIndexBufferTests() {
+    const AgcDriver::Pm4::DrawParameters automatic{0, 96, 0, 1, 0, false};
+    const auto unindexed = AgcDriver::Graphics::MeshIndexBufferDescriptor(automatic);
+    Require(unindexed[0] == 0 && unindexed[1] == 0 && unindexed[2] == 0 && unindexed[3] == 0x31016facu, "a non-indexed mesh draw did not get a null index buffer V#");
+    const AgcDriver::Pm4::DrawParameters indexed{0x123456789a00ull, 5, 2, 1, 0, true};
+    const auto words = AgcDriver::Graphics::MeshIndexBufferDescriptor(indexed);
+    Require(words[0] == 0x56789a00u && words[1] == 0x1234u && words[2] == 12u && words[3] == 0x31016facu, "an indexed mesh draw's index buffer V# changed");
+    expectFailure([] { static_cast<void>(AgcDriver::Graphics::MeshIndexBufferDescriptor(AgcDriver::Pm4::DrawParameters{0, 3, 2, 1, 0, true})); }, "invalid mesh index buffer range");
+}
+
 void meshArgumentTests() {
     using AgcDriver::Graphics::MeshArguments;
     using AgcDriver::Graphics::ResolveMeshArguments;
@@ -2105,6 +2115,7 @@ int main() {
         misalignedShaderDataTests();
         debugBranchTests();
         meshArgumentTests();
+        meshIndexBufferTests();
         validationTests();
         vertexCopyTests();
         pixelParameterSlotTests();
diff --git a/core/libs/prx/libSceAgcDriver/tests/Mesh.cpp b/core/libs/prx/libSceAgcDriver/tests/Mesh.cpp
index 025817a38..3257e4d73 100644
--- a/core/libs/prx/libSceAgcDriver/tests/Mesh.cpp
+++ b/core/libs/prx/libSceAgcDriver/tests/Mesh.cpp
@@ -122,7 +122,7 @@ struct MeshDraw {
 void DrawMesh(AgcDriver::VulkanDevice& device, const MeshDraw& setup) {
     const auto target = device.Target();
     std::vector<std::uint32_t> userData(12, 0u);
-    const auto index = AgcDriver::Graphics::MeshIndexBufferDescriptor(setup.draw, reinterpret_cast<std::uintptr_t>(GeometryCode.data()));
+    const auto index = AgcDriver::Graphics::MeshIndexBufferDescriptor(setup.draw);
     std::copy(index.begin(), index.end(), userData.begin() + ShaderRecompiler::MeshIndexBufferUserWord);
     std::copy(setup.vertexBuffer.begin(), setup.vertexBuffer.end(), userData.begin() + 8);
     const std::array<ShaderRecompiler::MemoryRegion, 1> geometryMemory{{{reinterpret_cast<std::uintptr_t>(GeometryCode.data()), std::as_bytes(std::span(GeometryCode))}}};