1 files changed, 2 insertions, 2 deletions

diff --git a/tr.c b/tr.c
index 15e3709bb..2717a92db 100644
--- a/tr.c
+++ b/tr.c
@@ -191,9 +191,9 @@ extern int tr_main(int argc, char **argv)
                         map(input, input_length, output, output_length);
                 }
                 for (i = 0; i < input_length; i++)
-                        invec[input[i]] = TRUE;
+                        invec[(int)input[i]] = TRUE;
                 for (i = 0; i < output_length; i++)
-                        outvec[output[i]] = TRUE;
+                        outvec[(int)output[i]] = TRUE;
         }
         convert();
         return (0);