diff --git a/parse.y b/parse.y
index 83d5b9f2..91bf3bf6 100644
--- a/parse.y
+++ b/parse.y
@@ -2424,7 +2424,7 @@ shell_getc (remove_quoted_newline)
 	 not already end in an EOF character.  */
       if (shell_input_line_terminator != EOF)
 	{
-	  if (shell_input_line_size < SIZE_MAX && shell_input_line_len > shell_input_line_size - 3)
+	  if (shell_input_line_size < SIZE_MAX-3 && (shell_input_line_len+3 > shell_input_line_size))
 	    shell_input_line = (char *)xrealloc (shell_input_line,
 					1 + (shell_input_line_size += 2));
 
diff --git a/patchlevel.h b/patchlevel.h
index 4099c48c..2860f131 100644
--- a/patchlevel.h
+++ b/patchlevel.h
@@ -25,6 +25,6 @@
    regexp `^#define[ 	]*PATCHLEVEL', since that's what support/mkversion.sh
    looks for to find the patch level (for the sccs version string). */
 
-#define PATCHLEVEL 8
+#define PATCHLEVEL 9
 
 #endif /* _PATCHLEVEL_H_ */
diff --git a/y.tab.c b/y.tab.c
index 709a56a3..80fe9308 100644
--- a/y.tab.c
+++ b/y.tab.c
@@ -4736,7 +4736,7 @@ shell_getc (remove_quoted_newline)
 	 not already end in an EOF character.  */
       if (shell_input_line_terminator != EOF)
 	{
-	  if (shell_input_line_size < SIZE_MAX && shell_input_line_len > shell_input_line_size - 3)
+	  if (shell_input_line_size < SIZE_MAX-3 && (shell_input_line_len+3 > shell_input_line_size))
 	    shell_input_line = (char *)xrealloc (shell_input_line,
 					1 + (shell_input_line_size += 2));