diff --git a/src/wic/plugins/source/bootimg_efi.py b/src/wic/plugins/source/bootimg_efi.py
index fe6c222..6c206ca 100644
--- a/src/wic/plugins/source/bootimg_efi.py
+++ b/src/wic/plugins/source/bootimg_efi.py
@@ -419,7 +419,7 @@ class BootimgEFIPlugin(SourcePlugin):
         sector_size = getattr(creator, 'sector_size', 512)
         dosfs_cmd = "mkdosfs -v -n %s -i %s -S %d -C %s %d" % \
                     (label, part.fsuuid, sector_size, bootimg, blocks)
-        exec_native_cmd(dosfs_cmd, native_sysroot)
+        out = exec_native_cmd(dosfs_cmd, native_sysroot)
         logger.debug("mkdosfs:\n%s" % (str(out)))
 
         mcopy_cmd = "mcopy -v -p -i %s -s %s/* ::/" % (bootimg, hdddir)