1 files changed, 3 insertions, 1 deletions
diff --git a/examples/Kaleidoscope/Chapter7/toy.cpp b/examples/Kaleidoscope/Chapter7/toy.cpp
index beb0c00..0062801 100644
--- a/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -109,10 +109,12 @@ static int gettok() {
 /// ExprAST - Base class for all expression nodes.
 class ExprAST {
 public:
-  virtual ~ExprAST() {}
+  virtual ~ExprAST();
   virtual Value *Codegen() = 0;
 };
 
+ExprAST::~ExprAST() {}
+
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
   double Val;