--- wdiff-0.5-orig/wdiff.c
+++ wdiff-0.5/wdiff.c
@@ -895,7 +895,7 @@
   /* Launch the diff program.  */
 
   if (ignore_case)
-    input_file = readpipe (DIFF_PROGRAM, "-c", left_side->temp_name,
+    input_file = readpipe (DIFF_PROGRAM, "-i", left_side->temp_name,
 			   right_side->temp_name, NULL);
   else
     input_file = readpipe (DIFF_PROGRAM, left_side->temp_name,