diff --git a/ExprNode.hh b/ExprNode.hh
index 048196ca..bef4a415 100644
--- a/ExprNode.hh
+++ b/ExprNode.hh
@@ -34,7 +34,6 @@ using namespace std;
 class DataTree;
 class VariableNode;
 class BinaryOpNode;
-class SymbolTable;
 
 typedef class ExprNode *expr_t;
 
diff --git a/ExternalFunctionsTable.hh b/ExternalFunctionsTable.hh
index 0dfe698a..b5218bea 100644
--- a/ExternalFunctionsTable.hh
+++ b/ExternalFunctionsTable.hh
@@ -28,7 +28,6 @@ using namespace std;
 #include <map>
 
 #include "SymbolTable.hh"
-class SymbolTable;
 
 enum ExternalFunctionSetOrNot
   {