diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9c75c3210..d6edad5be 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -213,7 +213,7 @@ set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 set(CMAKE_C_FLAGS_DEBUG "-Og -g")
 set(CMAKE_C_FLAGS_MINSIZEREL "-Os -DNDEBUG")
-set(CMAKE_C_FLAGS_RELEASE "-O4 -DNDEBUG")
+set(CMAKE_C_FLAGS_RELEASE "-O3 -DNDEBUG")
 set(CMAKE_C_FLAGS_RELWITHDEBINFO "-O2 -g")
 
 set(CMAKE_SHARED_LINKER_FLAGS "-Wl,--no-undefined -Wl,--fatal-warnings ${CMAKE_SHARED_LINKER_FLAGS}")