diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
index f9b0dbdb75..2a56c44a56 100644
--- a/src/backend/parser/scan.l
+++ b/src/backend/parser/scan.l
@@ -24,7 +24,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.127 2005/06/26 19:16:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.128 2005/08/16 00:48:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -633,6 +633,15 @@ other			.
 							return yytext[0];
 					}
 
+					/*
+					 * Complain if operator is too long.  Unlike the case
+					 * for identifiers, we make this an error not a notice-
+					 * and-truncate, because the odds are we are looking at
+					 * a syntactic mistake anyway.
+					 */
+					if (nchars >= NAMEDATALEN)
+						yyerror("operator too long");
+
 					/* Convert "!=" operator to "<>" for compatibility */
 					if (strcmp(yytext, "!=") == 0)
 						yylval.str = pstrdup("<>");