diff --git a/CMakeLists.txt b/CMakeLists.txt
index 26a8010d1..222fa5b72 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,6 +19,8 @@ else()
 	set(LLVM_LIBS "-lLLVMBitWriter -lLLVMX86CodeGen -lLLVMSelectionDAG -lLLVMAsmPrinter -lLLVMCodeGen -lLLVMScalarOpts -lLLVMInstCombine -lLLVMTransformUtils -lLLVMipa -lLLVMAnalysis -lLLVMX86AsmParser -lLLVMX86Desc -lLLVMX86Info -lLLVMX86AsmPrinter -lLLVMX86Utils -lLLVMMCJIT -lLLVMTarget -lLLVMRuntimeDyld -lLLVMObject -lLLVMMCParser -lLLVMBitReader -lLLVMExecutionEngine -lLLVMMC -lLLVMCore -lLLVMSupport -lz -lpthread -lffi -ltinfo -ldl -lm")
 endif()
 
+add_definitions(-D_SCL_SECURE_NO_WARNINGS) # LLVM needs it on Windows
+
 # Boost
 find_package(Boost REQUIRED)