diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 8578b5c7cb5..c2410efbba0 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.269.2.1 2008/05/03 23:19:27 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.269.2.2 2008/06/06 17:59:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -4472,10 +4472,19 @@ get_const_expr(Const *constval, deparse_context *context, int showtype)
 				 *
 				 * In reality we only need to defend against infinity and NaN,
 				 * so we need not get too crazy about pattern matching here.
+				 *
+				 * There is a special-case gotcha: if the constant is signed,
+				 * we need to parenthesize it, else the parser might see a
+				 * leading plus/minus as binding less tightly than adjacent
+				 * operators --- particularly, the cast that we might attach
+				 * below.
 				 */
 				if (strspn(extval, "0123456789+-eE.") == strlen(extval))
 				{
-					appendStringInfoString(buf, extval);
+					if (extval[0] == '+' || extval[0] == '-')
+						appendStringInfo(buf, "(%s)", extval);
+					else
+						appendStringInfoString(buf, extval);
 					if (strcspn(extval, "eE.") != strlen(extval))
 						isfloat = true; /* it looks like a float */
 				}