diff --git a/src/stuff.c b/src/stuff.c
index 26ad4a61c8d0909e51de1a07579e1e904f912cd3..3ac263db9119b62a88194c924a7c70761fe93af9 100644
--- a/src/stuff.c
+++ b/src/stuff.c
@@ -10,7 +10,7 @@
 
 int my_log2(unsigned INT32 x)
 {
-  static char bit[256] =
+  static signed char bit[256] =
   {
     -1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 
      4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,