Actuation unit for a stroller braking device, comprising - a housing with an upper housing part and a lower housing part, - an actuation handle arranged between the upper housing part and the lower housing part, the handle being supported in the housing for pivoting around a pivot axis and comprising a receptacle to which a coupling element can be fastened for operative connection of the actuation handle with the stroller braking device, - wherein the actuation handle, starting from an intermediate position, is pivotable in a first direction to a first pivotal position to generate a braking function of the stroller brake device and, also starting from an intermediate position, is pivotable in a second direction opposite to the first direction to a second pivotal position to generate a locking function of the stroller brake device, and - a releasable locking device for automatically locking the actuation handle in the second pivotal position, characterized in - that the locking device comprises a release button arranged for axial displacement on a pin coaxial with the pivot axis and at least one locking projection for dipping into a corresponding locking recess of the actuation handle, the projection being coupled with the release button, - that the locking device is provided with a preloading element for exerting a preloading force on the locking projection in the direction of the actuation handle for a automatic dipping of the locking projection into the locking recess when the actuation handle is in its second pivotal position, and - that, in the second pivotal position of the actuation handle and thus with the locking projection dipped into the locking recess, the release button assumes a release position in which the release button projects in part from the housing and, for releasing the locking device, the button is manually retractable into the housing against the preloading force up to a retracted position and remains in the retracted position in other pivotal positions of the actuation handle. - a housing with an upper housing part and a lower housing part, - an actuation handle arranged between the upper housing part and the lower housing part, the handle being supported in the housing for pivoting around a pivot axis and comprising a receptacle to which a coupling element can be fastened for operative connection of the actuation handle with the stroller braking device, - wherein the actuation handle, starting from an intermediate position, is pivotable in a first direction to a first pivotal position to generate a braking function of the stroller brake device and, also starting from an intermediate position, is pivotable in a second direction opposite to the first direction to a second pivotal position to generate a locking function of the stroller brake device, and - a releasable locking device for automatically locking the actuation handle in the second pivotal position, - that the locking device comprises a release button arranged for axial displacement on a pin coaxial with the pivot axis and at least one locking projection for dipping into a corresponding locking recess of the actuation handle, the projection being coupled with the release button, - that the locking device is provided with a preloading element for exerting a preloading force on the locking projection in the direction of the actuation handle for a automatic dipping of the locking projection into the locking recess when the actuation handle is in its second pivotal position, and - that, in the second pivotal position of the actuation handle and thus with the locking projection dipped into the locking recess, the release button assumes a release position in which the release button projects in part from the housing and, for releasing the locking device, the button is manually retractable into the housing against the preloading force up to a retracted position and remains in the retracted position in other pivotal positions of the actuation handle.