diff --git a/expat/CMakeLists.txt b/expat/CMakeLists.txt
index 9ba93f40..76e99c39 100644
--- a/expat/CMakeLists.txt
+++ b/expat/CMakeLists.txt
@@ -39,7 +39,10 @@ endif(BUILD_tests)
 
 include(${CMAKE_CURRENT_LIST_DIR}/ConfigureChecks.cmake)
 
-set(EXTRA_LINK_AND_COMPILE_FLAGS "-fno-strict-aliasing")
+set(EXTRA_LINK_AND_COMPILE_FLAGS)
+if(FLAG_NO_STRICT_ALIASING)
+    set(EXTRA_LINK_AND_COMPILE_FLAGS "${EXTRA_LINK_AND_COMPILE_FLAGS} -fno-strict-aliasing")
+endif()
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EXTRA_LINK_AND_COMPILE_FLAGS}")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${EXTRA_LINK_AND_COMPILE_FLAGS}")
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${EXTRA_LINK_AND_COMPILE_FLAGS}")
diff --git a/expat/ConfigureChecks.cmake b/expat/ConfigureChecks.cmake
index 2771a743..6e440ca0 100644
--- a/expat/ConfigureChecks.cmake
+++ b/expat/ConfigureChecks.cmake
@@ -1,3 +1,4 @@
+include(CheckCCompilerFlag)
 include(CheckIncludeFile)
 include(CheckIncludeFiles)
 include(CheckFunctionExists)
@@ -42,3 +43,5 @@ endif(HAVE_SYS_TYPES_H)
 
 configure_file(expat_config.h.cmake "${CMAKE_CURRENT_BINARY_DIR}/expat_config.h")
 add_definitions(-DHAVE_EXPAT_CONFIG_H)
+
+check_c_compiler_flag("-fno-strict-aliasing" FLAG_NO_STRICT_ALIASING)