--- a/src/util.cc
+++ b/src/util.cc
@@ -30,6 +30,11 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+// Redox: the C++ <cstdlib> wrapper pulls in a stale toolchain stdlib.h that
+// lacks getloadavg. Re-declare it here since relibc provides the implementation.
+#if defined(__redox__)
+extern "C" int getloadavg(double loadavg[], int nelem);
+#endif
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>