diff --git a/expat/CMakeLists.txt b/expat/CMakeLists.txt
index d79b9b16..8c37c59e 100644
--- a/expat/CMakeLists.txt
+++ b/expat/CMakeLists.txt
@@ -311,6 +311,10 @@ if (EXPAT_WARNINGS_AS_ERRORS)
         add_definitions(/WX)
     else()
         set(EXTRA_COMPILE_FLAGS "${EXTRA_COMPILE_FLAGS} -Werror")
+        if(MINGW)
+            # To avoid "error: unknown conversion type character ‘l’ in format [-Werror=format=]"
+            set(EXTRA_COMPILE_FLAGS "${EXTRA_COMPILE_FLAGS} -Wno-format")
+        endif()
     endif()
 endif()
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EXTRA_COMPILE_FLAGS}")