A crop harvesting header with a cutter bar and a draper assembly has a draper which includes a front edge of the upper run of the draper arranged at a position adjacent to but spaced from the cutter bar and there is provided a sealing member extending along the cutter bar. The sealing member is includes a bracket and a strip of flexible material where the bracket does not include any rearwardly extending biasing portion and the strip, when free from loading forces, contains a distortion from a flat form so that the second edge portion is distorted from a plane of the first edge portion in a direction toward the edge portion of the upper run.