diff --git a/CMakeLists.txt b/CMakeLists.txt
index bfc8a2283f..dad3815373 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -114,14 +114,7 @@ set(NVIM_API_LEVEL 11)        # Bump this after any API change.
 set(NVIM_API_LEVEL_COMPAT 0)  # Adjust this after a _breaking_ API change.
 set(NVIM_API_PRERELEASE false)
 
-# Default to -O2 on release builds.
-if(CMAKE_C_FLAGS_RELEASE MATCHES "-O3")
-  message(STATUS "Replacing -O3 in CMAKE_C_FLAGS_RELEASE with -O2")
-  string(REPLACE "-O3" "-O2" CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE}")
-endif()
-
 # Build-type: RelWithDebInfo
-
 # /Og means something different in MSVC
 if(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
    set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO} -Og -g")