diff --git a/cmake/mode.DEV.cmake b/cmake/mode.DEV.cmake
index ff7825a4d0..276644e30c 100644
--- a/cmake/mode.DEV.cmake
+++ b/cmake/mode.DEV.cmake
@@ -4,8 +4,8 @@ set(CMAKE_CXX_FLAGS_DEV
   CACHE
   INTERNAL
   "")
-string(APPEND CMAKE_CXX_FLAGS_RELEASE
-  " -O${Seastar_OptimizationLevel_RELEASE}")
+string(APPEND CMAKE_CXX_FLAGS_DEV
+  " -O${Seastar_OptimizationLevel_DEV}")
 
 set(Seastar_DEFINITIONS_DEV
   SCYLLA_BUILD_MODE=devel