1 files changed, 1 insertions, 1 deletions
diff --git a/slant.c b/slant.c
index bcf02ee..a174011 100644
--- a/slant.c
+++ b/slant.c
@@ -28,7 +28,7 @@
 #include <string.h>
 #include <assert.h>
 #include <ctype.h>
-#include <math.h>
+#include <tgmath.h>
 
 #include "puzzles.h"