1 files changed, 5 insertions, 1 deletions
diff --git a/untangle.c b/untangle.c
index 558cce7..62d5897 100644
--- a/untangle.c
+++ b/untangle.c
@@ -32,7 +32,11 @@
 #include <assert.h>
 #include <ctype.h>
 #include <limits.h>
-#include <tgmath.h>
+#ifdef NO_TGMATH_H
+#  include <math.h>
+#else
+#  include <tgmath.h>
+#endif
 
 #include "puzzles.h"
 #include "tree234.h"