diff --git a/expat/CMakeLists.txt b/expat/CMakeLists.txt
index 0575f811..79287b5d 100644
--- a/expat/CMakeLists.txt
+++ b/expat/CMakeLists.txt
@@ -780,6 +780,7 @@ if(EXPAT_BUILD_FUZZERS)
         CMAKE_ARGS -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
         CMAKE_CACHE_ARGS -DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER} -DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}
         BUILD_BYPRODUCTS ${ProtobufMutator_LIBRARIES}
+        PATCH_COMMAND sed -e "s,-Werror, ," -e "s,CMAKE_CXX_STANDARD [0-9]\\+,CMAKE_CXX_STANDARD 17," -i.bak ${ProtobufMutator_PATH}/CMakeLists.txt
         UPDATE_COMMAND true
         INSTALL_COMMAND true)