Bug: https://bugs.gentoo.org/893464

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -248,7 +248,7 @@
 
 else ()
 set(CMAKE_CXX_FLAGS
-  "${CMAKE_CXX_FLAGS} -fPIC -Wall -std=gnu++11 -DUNICODE -DWCHAR_INCOMPATIBLE_XMLCH ${CMAKE_WXWINDOWS_CXX_FLAGS}")
+  "${CMAKE_CXX_FLAGS} -fPIC -Wall  -DUNICODE -DWCHAR_INCOMPATIBLE_XMLCH ${CMAKE_WXWINDOWS_CXX_FLAGS}")
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -D_DEBUG -DDEBUG")
 if (USE_ASAN)
   set(CMAKE_CXX_FLAGS_DEBUG