diff --git a/CMakeLists.txt b/CMakeLists.txt
index c4e5034..025b0d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,7 +15,7 @@ INCLUDE_DIRECTORIES (${CMAKE_CURRENT_BINARY_DIR})
 
 INCLUDE_DIRECTORIES (${CMAKE_SOURCE_DIR}/inc)
 
-ADD_DEFINITIONS("-std=c++0x")
+SET(CMAKE_CXX_FLAGS "-std=c++11")
 
 ADD_EXECUTABLE (lemon grammar/lemon.c)
 ADD_EXECUTABLE (makeheaders grammar/makeheaders.c)
diff --git a/inc/AST/CodeGenVisitor.h b/inc/AST/CodeGenVisitor.h
index ef83cdb..2c1c407 100644
--- a/inc/AST/CodeGenVisitor.h
+++ b/inc/AST/CodeGenVisitor.h
@@ -2,6 +2,11 @@
 #define CODEGENVISITOR_H
 
 #include "ASTVisitor.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/IRBuilder.h"
+#include "llvm/LLVMContext.h"
+#include "llvm/Module.h"
+#include "llvm/Analysis/Verifier.h"
 #include <string>
 
 class CodeGenVisitor : public ASTVisitor {