diff --git a/CMakeLists.txt b/CMakeLists.txt
index b4fe429d..873979dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@ set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
-    set(CMAKE_CXX_FLAGS "-Wall ${CMAKE_CXX_FLAGS}")
+    set(CMAKE_CXX_FLAGS "-Wall -O3 ${CMAKE_CXX_FLAGS}")
 endif()
 
 #---------------------------------------------------------------------------------------