diff --git a/lib/extentwalker.cc b/lib/extentwalker.cc
index 8fa883d..83f430e 100644
--- a/lib/extentwalker.cc
+++ b/lib/extentwalker.cc
@@ -496,7 +496,7 @@ namespace crucible {
 	BtrfsExtentWalker::Vec
 	BtrfsExtentWalker::get_extent_map(off_t pos)
 	{
-		BtrfsIoctlSearchKey sk(65536);
+		BtrfsIoctlSearchKey sk;
 		if (!m_root_fd) {
 			m_root_fd = m_fd;
 		}