diff --git a/src/core/include/mp-units/bits/core_gmf.h b/src/core/include/mp-units/bits/core_gmf.h
index e37d8d8f..e2197162 100644
--- a/src/core/include/mp-units/bits/core_gmf.h
+++ b/src/core/include/mp-units/bits/core_gmf.h
@@ -41,6 +41,7 @@
 #include <random>
 #include <ranges>
 #include <sstream>
+#include <string>
 #include <string_view>
 #include <tuple>
 #include <type_traits>