diff --git a/unit_tests/CMakeLists.txt b/unit_tests/CMakeLists.txt
index f64f6d51f0..6a66269104 100644
--- a/unit_tests/CMakeLists.txt
+++ b/unit_tests/CMakeLists.txt
@@ -9,9 +9,17 @@ project(igdrcl_tests)
 set(TEST_PROJECTS_FOLDER "opencl runtime")
 set(PLATFORM_SPECIFIC_TARGETS_FOLDER "${TEST_PROJECTS_FOLDER}/test platforms")
 
+# disable optimizations for ults
+string(REPLACE "-O2" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
+
+if(UNIX)
+  #disable fortify source as this requires optimization to be on
+  string(REPLACE "-D_FORTIFY_SOURCE=2" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
+  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O0")
+  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -O0")
+endif()
+
 if(WIN32)
-  # disable optimizations for ults on Windows
-  string(REPLACE "-O2" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
   set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Od")
   set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -Od")
   set(CMAKE_C_FLAGS_RELEASEINTERNAL "${CMAKE_C_FLAGS_RELEASE} -Od")