diff --git a/ChangeLog b/ChangeLog
index 1930fbdcf..c7312df28 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2006-05-18  Matthew Flatt  <mflatt@cs.utah.edu>
+
+	* lightning/i386/asm.h: Fix test for extending the mprotect area
+	towards lower addresses.
+
 2006-05-16  Bruno Haible  <bruno@clisp.org>
 
 	* lightning/asm-common.h: Don't use __func__ nor __FUNCTION__ if
diff --git a/lightning/i386/funcs.h b/lightning/i386/funcs.h
index d57e14e25..ee26d4699 100644
--- a/lightning/i386/funcs.h
+++ b/lightning/i386/funcs.h
@@ -74,12 +74,13 @@ jit_flush_code(void *dest, void *end)
 
   /* See if we can extend the previously mprotect'ed memory area towards
      higher addresses: the starting address remains the same as before.  */
-  if (page >= prev_page && page <= prev_page + prev_length)
+  else if (page >= prev_page && page <= prev_page + prev_length)
     prev_length = page + length - prev_page;
 
   /* See if we can extend the previously mprotect'ed memory area towards
      lower addresses: the highest address remains the same as before.  */
-  else if (page < prev_page && page + length <= prev_page + prev_length)
+  else if (page < prev_page && page + length >= prev_page
+          && page + length <= prev_page + prev_length)
     prev_length += prev_page - page, prev_page = page;
 
   /* Nothing to do, replace the area.  */