diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index c068be575..54dad55c6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -773,6 +773,10 @@ else()
 	set(CMAKE_CXX_FLAGS_SEMIDEBUG "-g -O1 ${WARNING_FLAGS} ${OTHER_FLAGS}")
 	set(CMAKE_CXX_FLAGS_DEBUG "-g -O0 ${WARNING_FLAGS} ${OTHER_FLAGS}")
 
+	if(UNIX)
+		# enable assertions for libstdc++ or libc++
+		set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wp,-D_GLIBCXX_ASSERTIONS -Wp,-D_LIBCPP_ENABLE_ASSERTIONS=1")
+	endif()
 	if(USE_GPROF)
 		set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -pg")
 	endif()