Index: src/wp-admin/includes/plugin-install.php
===================================================================
--- src/wp-admin/includes/plugin-install.php	(revision 38250)
+++ src/wp-admin/includes/plugin-install.php	(working copy)
@@ -262,8 +262,8 @@
 			<option value="author"<?php selected( 'author', $type ); ?>><?php _e( 'Author' ); ?></option>
 			<option value="tag"<?php selected( 'tag', $type ); ?>><?php _ex( 'Tag', 'Plugin Installer' ); ?></option>
 		</select>
-		<label><span class="screen-reader-text"><?php _e( 'Search Plugins' ); ?></span>
-			<input type="search" name="s" value="<?php echo esc_attr( $term ) ?>" class="wp-filter-search" placeholder="<?php esc_attr_e( 'Search Plugins' ); ?>" />
+		<label for="wp-filter-search-input"><span class="screen-reader-text"><?php _e( 'Search Plugins' ); ?></span>
+			<input type="search" id="wp-filter-search-input" name="s" value="<?php echo esc_attr( $term ) ?>" class="wp-filter-search" placeholder="<?php esc_attr_e( 'Search Plugins' ); ?>" />
 		</label>
 		<?php submit_button( __( 'Search Plugins' ), 'button hide-if-js', false, false, array( 'id' => 'search-submit' ) ); ?>
 	</form><?php