--- a/build/moz.configure/warnings.configure
+++ b/build/moz.configure/warnings.configure
@@ -101,16 +101,20 @@ check_and_add_gcc_warning('-Wno-error=fr
 
 # Would be a pain to fix all occurrences, for very little gain
 check_and_add_gcc_warning('-Wno-error=multistatement-macros')
 
 # Disable the -Werror for return-std-move because of a false positive
 # on nsTAutoStringN: https://bugs.llvm.org/show_bug.cgi?id=37249
 check_and_add_gcc_warning('-Wno-error=return-std-move')
 
+# Disable the -Werror for -Wclass-memaccess as we have a long
+# tail of issues to fix
+check_and_add_gcc_warning('-Wno-error=class-memaccess')
+
 # catches format/argument mismatches with printf
 c_format_warning, cxx_format_warning = check_and_add_gcc_warning(
     '-Wformat', when=depends(target)(lambda t: t.kernel != 'WINNT'))
 
 # Add compile-time warnings for unprotected functions and format functions
 # that represent possible security problems. Enable this only when -Wformat
 # is enabled, otherwise it is an error
 check_and_add_gcc_warning('-Wformat-security',