diff -Nur haproxy-1.3.18/src/proto_tcp.c haproxy-1.3.18-tcp-request-condition-fix/src/proto_tcp.c
--- haproxy-1.3.18/src/proto_tcp.c	2009-05-10 20:27:47.000000000 +0200
+++ haproxy-1.3.18-tcp-request-condition-fix/src/proto_tcp.c	2009-05-12 01:25:48.000000000 +0200
@@ -509,6 +509,13 @@
 			pol = ACL_COND_IF;
 		else if (!strcmp(args[3], "unless"))
 			pol = ACL_COND_UNLESS;
+		else {
+			if (args[3][0] != '\0') {
+				snprintf(err, errlen, "'%s %s %s' expects 'if', 'unless' or nothing, but found '%s'",
+					 args[0], args[1], args[2], args[3]);
+				return -1;
+			}
+		}
 
 		/* Note: we consider "if TRUE" when there is no condition */
 		if (pol != ACL_COND_NONE &&