diff --git a/Python/pymath.c b/Python/pymath.c
index 5cf61ab74c6..6b8def9f71f 100644
--- a/Python/pymath.c
+++ b/Python/pymath.c
@@ -22,7 +22,7 @@ double hypot(double x, double y)
 #endif /* HAVE_HYPOT */
 
 #ifndef HAVE_COPYSIGN
-static double
+double
 copysign(double x, double y)
 {
 	/* use atan2 to distinguish -0. from 0. */