1 files changed, 1 insertions, 1 deletions
diff --git a/range.c b/range.c
index 293b6cb..45ab10b 100644
--- a/range.c
+++ b/range.c
@@ -58,7 +58,7 @@
 #include <string.h>
 #include <assert.h>
 #include <ctype.h>
-#include <math.h>
+#include <tgmath.h>
 
 #include "puzzles.h"