diff --git a/CMakeLists.txt b/CMakeLists.txt
index e08a44d6a..6727d06ad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -42,7 +42,7 @@ add_definitions(${LLVM_DEFINITIONS})
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_CXX_STANDARD 17)
 
-set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")
+set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O1")
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -O3")
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -gdwarf-3")