1 files changed, 1 insertions, 1 deletions
diff --git a/undead.c b/undead.c
index 833eb34..4ef8fe4 100644
--- a/undead.c
+++ b/undead.c
@@ -35,7 +35,7 @@
 #include <string.h>
 #include <assert.h>
 #include <ctype.h>
-#include <math.h>
+#include <tgmath.h>
 
 #include "puzzles.h"