1 files changed, 5 insertions, 1 deletions
diff --git a/hat.c b/hat.c
index 99babcc..dbb8f41 100644
--- a/hat.c
+++ b/hat.c
@@ -12,7 +12,11 @@
  */
 
 #include <assert.h>
-#include <tgmath.h>
+#ifdef NO_TGMATH_H
+#  include <math.h>
+#else
+#  include <tgmath.h>
+#endif
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>