diff --git a/CMakeLists.txt b/CMakeLists.txt
index c774e62f..05893851 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,7 +41,7 @@ if(USE_GCOV)
 endif(USE_GCOV)
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -g")
-set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS} -O1")
+set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS} -O0")
 
 if(NOT DISABLE_ASAN)
   set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS} -fsanitize=address")