diff --git a/src/gnudiff_analyze.cpp b/src/gnudiff_analyze.cpp
index ea49b4e..0661a00 100644
--- a/src/gnudiff_analyze.cpp
+++ b/src/gnudiff_analyze.cpp
@@ -469,7 +469,7 @@ void GnuDiff::discard_confusing_lines (struct file_data filevec[])
   for (f = 0; f < 2; f++)
     {
       lin end = filevec[f].buffered_lines;
-      register char *discards = discarded[f];
+      char *discards = discarded[f];
 
       for (i = 0; i < end; i++)
 	{
@@ -479,7 +479,7 @@ void GnuDiff::discard_confusing_lines (struct file_data filevec[])
 	  else if (discards[i] != 0)
 	    {
 	      /* We have found a nonprovisional discard.  */
-	      register lin j;
+	      lin j;
 	      lin length;
 	      lin provisional = 0;
 
@@ -511,7 +511,7 @@ void GnuDiff::discard_confusing_lines (struct file_data filevec[])
 		}
 	      else
 		{
-		  register lin consec;
+		  lin consec;
 		  lin minimum = 1;
 		  lin tem = length >> 2;