diff --git a/Python/hypot.c b/Python/hypot.c
index 9d3c0d0..a18ce16 100644
--- a/Python/hypot.c
+++ b/Python/hypot.c
@@ -2,6 +2,7 @@
 
 #include "Python.h"
 
+#ifndef HAVE_HYPOT
 double hypot(double x, double y)
 {
 	double yx;
@@ -20,3 +21,5 @@
 		return x*sqrt(1.+yx*yx);
 	}
 }
+#endif /* HAVE_HYPOT */
+