diff --git a/meson.build b/meson.build
index 4547fc8..6e312df 100644
--- a/meson.build
+++ b/meson.build
@@ -87,7 +87,12 @@ if is_dist_check
 else
   cpp_warnings = get_option('warnings')
 endif
-warning_level = get_option('warning_level').to_int()
+if get_option('warning_level') in ['0','1','2','3','4','5']
+  warning_level = get_option('warning_level').to_int()
+else
+  # For instance get_option('warning_level') == 'everything'
+  warning_level = 99
+endif
 werror = get_option('werror')
 build_deprecated_api = get_option('build-deprecated-api')
 build_documentation_opt = get_option('build-documentation')