diff --git a/src/ast/ast_const_folding.cpp b/src/ast/ast_const_folding.cpp
index 0c981af06..6b5fbdf9a 100644
--- a/src/ast/ast_const_folding.cpp
+++ b/src/ast/ast_const_folding.cpp
@@ -38,9 +38,9 @@ namespace das {
 
     class NoSideEffectVisitor : public Visitor {
     protected:
-        virtual bool canVisitStructureFieldInit ( Structure * ) override { return false; }
-        virtual bool canVisitArgumentInit ( Function * , const VariablePtr &, Expression * ) override { return false; }
-        virtual bool canVisitQuoteSubexpression ( ExprQuote * ) override { return false; }
+        // virtual bool canVisitStructureFieldInit ( Structure * ) override { return false; }
+        // virtual bool canVisitArgumentInit ( Function * , const VariablePtr &, Expression * ) override { return false; }
+        // virtual bool canVisitQuoteSubexpression ( ExprQuote * ) override { return false; }
     // make block
         virtual void preVisit ( ExprMakeBlock * expr ) override {
             Visitor::preVisit(expr);
@@ -453,9 +453,9 @@ namespace das {
             return nullptr;
         }
     protected:
-        virtual bool canVisitStructureFieldInit ( Structure * ) override { return false; }
-        virtual bool canVisitArgumentInit ( Function * , const VariablePtr &, Expression * ) override { return false; }
-        virtual bool canVisitQuoteSubexpression ( ExprQuote * ) override { return false; }
+        // virtual bool canVisitStructureFieldInit ( Structure * ) override { return false; }
+        // virtual bool canVisitArgumentInit ( Function * , const VariablePtr &, Expression * ) override { return false; }
+        // virtual bool canVisitQuoteSubexpression ( ExprQuote * ) override { return false; }
     // swizzle
         virtual ExpressionPtr visit ( ExprSwizzle * expr ) override {
             if ( expr->type->baseType == expr->value->type->baseType ) {
diff --git a/src/ast/ast_infer_type.cpp b/src/ast/ast_infer_type.cpp
index 159245e16..16030fad9 100644
--- a/src/ast/ast_infer_type.cpp
+++ b/src/ast/ast_infer_type.cpp
@@ -1938,7 +1938,7 @@ namespace das {
                     }
                 }
             }
-            if ( decl.parentType ) {
+            if ( decl.parentType && st->parent ) {
                 auto pf = st->parent->findField(decl.name);
                 if ( !pf->type->isAutoOrAlias() ) {
                     decl.type = make_smart<TypeDecl>(*pf->type);