Waiver of appeal may be a valid term of a plea negotiation and challenging that waiver requires a certificate of probable cause. Appellant filed a motion to suppress evidence pursuant to Penal Code section 1538.5, which the court denied. He then entered into a plea negotiation whereby he pled no contest to one drug count and waived his right to appeal. Appellant here appealed the denial of the suppression motion, contending that his waiver of appeal was not knowing and intelligent. No certificate of probable cause was obtained. Held: appeal dismissed. Under Penal Code section 1237.5, a defendant may not appeal from a judgment of conviction following a guilty or no contest plea unless he files a statement with the trial court showing reasonable, constitutional, jurisdictional, or other grounds going to the legality of the proceedings and the trial court executes a certificate of probable cause. Rules of Court, rule 8.304(b)(4) provides an exception from the probable cause certificate requirement if the appeal is from the denial of a motion to suppress or grounds that do not affect the plea’s validity. A plea bargain may include a waiver of the right to appeal. If the bargain includes an express waiver, an attempt to appeal the denial of a suppression motion would be an attack on the plea necessitating a certificate of probable cause. Here, because no certificate was obtained, the appeal was inoperable. A challenge to the validity of the waiver would also require a certificate of probable cause.