diff --git a/dlls/d3dcompiler_43/reflection.c b/dlls/d3dcompiler_43/reflection.c
index 89f868b978c..a7aef62114b 100644
--- a/dlls/d3dcompiler_43/reflection.c
+++ b/dlls/d3dcompiler_43/reflection.c
@@ -143,9 +143,19 @@ static HRESULT STDMETHODCALLTYPE d3dcompiler_shader_reflection_GetResourceBindin
 static HRESULT STDMETHODCALLTYPE d3dcompiler_shader_reflection_GetInputParameterDesc(
         ID3D11ShaderReflection *iface, UINT index, D3D11_SIGNATURE_PARAMETER_DESC *desc)
 {
-    FIXME("iface %p, index %u, desc %p stub!\n", iface, index, desc);
+    struct d3dcompiler_shader_reflection *This = impl_from_ID3D11ShaderReflection(iface);
 
-    return E_NOTIMPL;
+    TRACE("iface %p, index %u, desc %p\n", iface, index, desc);
+
+    if (!desc || !This->isgn || index >= This->isgn->element_count)
+    {
+        WARN("Invalid argument specified\n");
+        return E_INVALIDARG;
+    }
+
+    *desc = This->isgn->elements[index];
+
+    return S_OK;
 }
 
 static HRESULT STDMETHODCALLTYPE d3dcompiler_shader_reflection_GetOutputParameterDesc(