Does a demurrer need leave to amend?

2 The procedural posture of this case is somewhat muddied because in opposition to respondent's demurrer, which was based on the face of the original complaint, appellant submitted a declaration. However, it is error to sustain a demurrer without leave to amend, if there is any reasonable probability the complaint can be amended to state a good cause of action. (Youngman v. Nevada Irrigation Dist. (1969) 70 Cal.2d 240, 244-245, 74 Cal.Rptr. 398, 449 P.2d 462.) Since we conclude the declaration of appellant's counsel shows appellant can allege facts entitling him to name respondent as a previously sued Doe, it was error to sustain the demurrer without leave to amend.