diff --git a/include/SFML/System/String.hpp b/include/SFML/System/String.hpp
index ee737529a..a5757c9e2 100644
--- a/include/SFML/System/String.hpp
+++ b/include/SFML/System/String.hpp
@@ -58,7 +58,7 @@ public:
     ////////////////////////////////////////////////////////////
     // NOLINTBEGIN(readability-identifier-naming)
     /// Represents an invalid position in the string
-    static inline const std::size_t InvalidPos{std::basic_string<std::uint32_t>::npos};
+    static constexpr std::size_t InvalidPos{std::basic_string<std::uint32_t>::npos};
     // NOLINTEND(readability-identifier-naming)
 
     ////////////////////////////////////////////////////////////