diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dbcc8ca4bb2..24096b199af 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+Tue Oct 19 01:26:48 1999  Alasdair Baird <alasdair@wildcat.demon.co.uk>
+
+	* fold-const.c (fold): Fix thinko in x+(-0) -> x transformation.
+
 Mon Oct 18 15:19:41 1999  Richard Henderson  <rth@cygnus.com>
 
 	* basic-block.h (set_block_num): Declare.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index f055d23a13d..24cc7529327 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -4871,7 +4871,8 @@ fold (expr)
 	       && real_zerop (arg1))
 	return non_lvalue (convert (type, arg0));
       /* x+(-0) equals x, even for IEEE.  */
-      else if (REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
+      else if (TREE_CODE (arg1) == REAL_CST
+	       && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
 	return non_lvalue (convert (type, arg0));
 
      bit_rotate: