diff --git a/include/pybind11/detail/type_caster_base.h b/include/pybind11/detail/type_caster_base.h
index 50a3b87950..aaf191a60e 100644
--- a/include/pybind11/detail/type_caster_base.h
+++ b/include/pybind11/detail/type_caster_base.h
@@ -792,7 +792,7 @@ class type_caster_generic {
                         matching_bases.push_back(base);
                     }
                 }
-                if (matching_bases.size() != 0) {
+                if (!matching_bases.empty()) {
                     if (matching_bases.size() > 1) {
                         matching_bases.push_back(const_cast<type_info *>(typeinfo));
                         all_type_info_check_for_divergence(matching_bases);