diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 6d94cbbcd2559..c61c03a36bac5 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -704,7 +704,7 @@ else()
   option(LLVM_ENABLE_ASSERTIONS "Enable assertions" ON)
 endif()
 
-option(LLVM_ENABLE_IO_SANDBOX "Enable IO sandboxing in supported tools" OFF)
+option(LLVM_ENABLE_IO_SANDBOX "Enable IO sandboxing in supported tools" ${LLVM_ENABLE_ASSERTIONS})
 option(LLVM_ENABLE_EXPENSIVE_CHECKS "Enable expensive checks" OFF)
 
 set(LLVM_ABI_BREAKING_CHECKS "WITH_ASSERTS" CACHE STRING