diff --git a/include/clad/Differentiator/StmtClone.h b/include/clad/Differentiator/StmtClone.h
index ee5d2e801..68b0daab2 100644
--- a/include/clad/Differentiator/StmtClone.h
+++ b/include/clad/Differentiator/StmtClone.h
@@ -50,7 +50,7 @@ namespace utils {
 
     /// Cloning types is necessary since VariableArrayType
     /// store a pointer to their size expression.
-    clang::QualType CloneType(const clang::QualType T);
+    clang::QualType CloneType(clang::QualType T);
 
   // visitor part (not for public use)
   // Stmt.def could be used if ABSTR_STMT is introduced
diff --git a/include/clad/Differentiator/VisitorBase.h b/include/clad/Differentiator/VisitorBase.h
index 9036c2c96..08a6201f8 100644
--- a/include/clad/Differentiator/VisitorBase.h
+++ b/include/clad/Differentiator/VisitorBase.h
@@ -560,7 +560,7 @@ namespace clad {
     clang::Expr* Clone(const clang::Expr* E);
     /// Cloning types is necessary since VariableArrayType
     /// store a pointer to their size expression.
-    clang::QualType CloneType(const clang::QualType T);
+    clang::QualType CloneType(clang::QualType T);
   };
 } // end namespace clad
 
diff --git a/lib/Differentiator/StmtClone.cpp b/lib/Differentiator/StmtClone.cpp
index 4dbbdd15d..3fd85853a 100644
--- a/lib/Differentiator/StmtClone.cpp
+++ b/lib/Differentiator/StmtClone.cpp
@@ -62,7 +62,7 @@ Stmt* StmtClone::Visit ## CLASS(CLASS *Node)            \
   clad_compat::ExprSetDeps(result, Node);               \
   return result;                                        \
 }
-
+// NOLINTBEGIN(modernize-use-auto)
 DEFINE_CLONE_EXPR_CO11(BinaryOperator, (CLAD_COMPAT_CLANG11_Ctx_ExtraParams Clone(Node->getLHS()), Clone(Node->getRHS()), Node->getOpcode(), CloneType(Node->getType()), Node->getValueKind(), Node->getObjectKind(), Node->getOperatorLoc(), Node->getFPFeatures(CLAD_COMPAT_CLANG11_LangOptions_EtraParams)))
 DEFINE_CLONE_EXPR_CO11(UnaryOperator, (CLAD_COMPAT_CLANG11_Ctx_ExtraParams Clone(Node->getSubExpr()), Node->getOpcode(), CloneType(Node->getType()), Node->getValueKind(), Node->getObjectKind(), Node->getOperatorLoc() CLAD_COMPAT_CLANG7_UnaryOperator_ExtraParams CLAD_COMPAT_CLANG11_UnaryOperator_ExtraParams))
 Stmt* StmtClone::VisitDeclRefExpr(DeclRefExpr *Node) {
@@ -102,14 +102,14 @@ Stmt* StmtClone::VisitMemberExpr(MemberExpr* Node) {
   return result;
 }
 DEFINE_CLONE_EXPR(CompoundLiteralExpr, (Node->getLParenLoc(), Node->getTypeSourceInfo(), CloneType(Node->getType()), Node->getValueKind(), Clone(Node->getInitializer()), Node->isFileScope()))
-DEFINE_CREATE_EXPR(ImplicitCastExpr, (Ctx, CloneType(Node->getType()), Node->getCastKind(), Clone(Node->getSubExpr()), 0, Node->getValueKind() /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node) ))
-DEFINE_CREATE_EXPR(CStyleCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), 0 /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node), Node->getTypeInfoAsWritten(), Node->getLParenLoc(), Node->getRParenLoc()))
-DEFINE_CREATE_EXPR(CXXStaticCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), 0, Node->getTypeInfoAsWritten() /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
-DEFINE_CREATE_EXPR(CXXDynamicCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), 0, Node->getTypeInfoAsWritten(), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
-DEFINE_CREATE_EXPR(CXXReinterpretCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), 0, Node->getTypeInfoAsWritten(), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
+DEFINE_CREATE_EXPR(ImplicitCastExpr, (Ctx, CloneType(Node->getType()), Node->getCastKind(), Clone(Node->getSubExpr()), nullptr, Node->getValueKind() /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node) ))
+DEFINE_CREATE_EXPR(CStyleCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), nullptr /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node), Node->getTypeInfoAsWritten(), Node->getLParenLoc(), Node->getRParenLoc()))
+DEFINE_CREATE_EXPR(CXXStaticCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), nullptr, Node->getTypeInfoAsWritten() /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
+DEFINE_CREATE_EXPR(CXXDynamicCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), nullptr, Node->getTypeInfoAsWritten(), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
+DEFINE_CREATE_EXPR(CXXReinterpretCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getCastKind(), Clone(Node->getSubExpr()), nullptr, Node->getTypeInfoAsWritten(), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
 DEFINE_CREATE_EXPR(CXXConstCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Clone(Node->getSubExpr()), Node->getTypeInfoAsWritten(), Node->getOperatorLoc(), Node->getRParenLoc(), Node->getAngleBrackets()))
 DEFINE_CREATE_EXPR(CXXConstructExpr, (Ctx, CloneType(Node->getType()), Node->getLocation(), Node->getConstructor(), Node->isElidable(), clad_compat::makeArrayRef(Node->getArgs(), Node->getNumArgs()), Node->hadMultipleCandidates(), Node->isListInitialization(), Node->isStdInitListInitialization(), Node->requiresZeroInitialization(), Node->getConstructionKind(), Node->getParenOrBraceRange()))
-DEFINE_CREATE_EXPR(CXXFunctionalCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getTypeInfoAsWritten(), Node->getCastKind(), Clone(Node->getSubExpr()), 0 /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node), Node->getLParenLoc(), Node->getRParenLoc()))
+DEFINE_CREATE_EXPR(CXXFunctionalCastExpr, (Ctx, CloneType(Node->getType()), Node->getValueKind(), Node->getTypeInfoAsWritten(), Node->getCastKind(), Clone(Node->getSubExpr()), nullptr /*EP*/CLAD_COMPAT_CLANG12_CastExpr_GetFPO(Node), Node->getLParenLoc(), Node->getRParenLoc()))
 DEFINE_CREATE_EXPR(ExprWithCleanups, (Ctx, Node->getSubExpr(),
                                       Node->cleanupsHaveSideEffects(), {}))
 // clang <= 7 do not have `ConstantExpr` node.
@@ -140,6 +140,7 @@ DEFINE_CLONE_EXPR(SubstNonTypeTemplateParmExpr, (CloneType(Node->getType()), Nod
 DEFINE_CLONE_EXPR(SubstNonTypeTemplateParmExpr, (CloneType(Node->getType()), Node->getValueKind(), Node->getBeginLoc(), Node->getReplacement(), Node->getAssociatedDecl(), Node->getIndex(), Node->getPackIndex(), Node->isReferenceParameter()));
 #endif
 DEFINE_CREATE_EXPR(PseudoObjectExpr, (Ctx, Node->getSyntacticForm(), llvm::SmallVector<Expr*, 4>(Node->semantics_begin(), Node->semantics_end()), Node->getResultExprIndex()))
+// NOLINTEND(modernize-use-auto)
 //BlockExpr
 //BlockDeclRefExpr
 
@@ -447,7 +448,7 @@ bool ReferencesUpdater::VisitStmt(clang::Stmt* S) {
 }
 
 void ReferencesUpdater::updateType(QualType QT) {
-  if (auto* varArrType = dyn_cast<VariableArrayType>(QT)) {
+  if (const auto* varArrType = dyn_cast<VariableArrayType>(QT)) {
     TraverseStmt(varArrType->getSizeExpr());
   }
 }