diff --git a/code/nel/include/nel/misc/string_common.h b/code/nel/include/nel/misc/string_common.h
index 4eca5d13d..1d6cf0fa2 100644
--- a/code/nel/include/nel/misc/string_common.h
+++ b/code/nel/include/nel/misc/string_common.h
@@ -205,8 +205,10 @@ inline std::string toString(const long unsigned int &val)
 #if (SIZEOF_SIZE_T) == 8
 inline std::string toString(const size_t &val) { return toString("%"NL_I64"u", val); }
 #else
+#ifdef NL_OS_MAC
 inline std::string toString(const size_t &val) { return toString("%u", val); }
 #endif
+#endif
 inline std::string toString(const float &val) { return toString("%f", val); }
 inline std::string toString(const double &val) { return toString("%lf", val); }
 inline std::string toString(const bool &val) { return toString("%u", val?1:0); }