diff --git a/lib/Differentiator/ReverseModeVisitor.cpp b/lib/Differentiator/ReverseModeVisitor.cpp
index 5a935fb78..7d01ec589 100644
--- a/lib/Differentiator/ReverseModeVisitor.cpp
+++ b/lib/Differentiator/ReverseModeVisitor.cpp
@@ -204,13 +204,8 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     assert(m_DiffReq.Function && "Must not be null.");
 
     DiffParams args{};
-    if (m_DiffReq.Args)
-      for (const auto& dParam : m_DiffReq.DVI)
-        args.push_back(dParam.param);
-    else
-      std::copy(FD->param_begin(), FD->param_end(), std::back_inserter(args));
-    if (args.empty())
-      return {};
+    for (const auto& dParam : m_DiffReq.DVI)
+      args.push_back(dParam.param);
 
     if (m_ExternalSource)
       m_ExternalSource->ActAfterParsingDiffArgs(m_DiffReq, args);
@@ -359,11 +354,8 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     assert(m_DiffReq.Function && "Must not be null.");
 
     DiffParams args{};
-    if (!m_DiffReq.DVI.empty())
-      for (const auto& dParam : m_DiffReq.DVI)
-        args.push_back(dParam.param);
-    else
-      std::copy(FD->param_begin(), FD->param_end(), std::back_inserter(args));
+    for (const auto& dParam : m_DiffReq.DVI)
+      args.push_back(dParam.param);
 #ifndef NDEBUG
     bool isStaticMethod = utils::IsStaticMethod(FD);
     assert((!args.empty() || !isStaticMethod) &&