diff --git a/linux-2.4.29-xen-sparse/mkbuildtree b/linux-2.4.29-xen-sparse/mkbuildtree
index a0e52c2c5c..d586153418 100755
--- a/linux-2.4.29-xen-sparse/mkbuildtree
+++ b/linux-2.4.29-xen-sparse/mkbuildtree
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # mkbuildtree <build tree>
 #
diff --git a/linux-2.6.10-xen-sparse/mkbuildtree b/linux-2.6.10-xen-sparse/mkbuildtree
index d353015ff2..8ab2d42a7c 100755
--- a/linux-2.6.10-xen-sparse/mkbuildtree
+++ b/linux-2.6.10-xen-sparse/mkbuildtree
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # mkbuildtree <build tree>
 #
diff --git a/netbsd-2.0-xen-sparse/mkbuildtree b/netbsd-2.0-xen-sparse/mkbuildtree
index 1877db8a5e..0d5330d115 100755
--- a/netbsd-2.0-xen-sparse/mkbuildtree
+++ b/netbsd-2.0-xen-sparse/mkbuildtree
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # mkbuildtree <build tree>
 #