1 files changed, 5 insertions, 1 deletions
diff --git a/src/math/atan2.c b/src/math/atan2.c
index f54c4cf7..38ba944e 100644
--- a/src/math/atan2.c
+++ b/src/math/atan2.c
@@ -2,11 +2,15 @@
 #include <math.h>
 #include "_tgmath.h"
 #include "errno.h"
-#include "../_assert.h"
+#include "_assert.h"
 
 #include "M_PI.c"
 #include "M_PI_2.c"
 
+#ifndef copysign
+#define copysign(_x, _y) _x
+#endif
+
 /** arc tangent **/
 TYPE TGFN(atan2)(TYPE y, TYPE x)
 {