diff --git a/bin/dib-lint b/bin/dib-lint
index f75c1ccd6..c58865e5c 100755
--- a/bin/dib-lint
+++ b/bin/dib-lint
@@ -151,6 +151,12 @@ for i in $(find elements -type f   \
         fi
     fi
 
+    # check that environment files don't "set -x"
+    if [[ "$i" =~ (environment.d) ]]; then
+        if grep -q "set -x" $i; then
+            error "Environment file $i should not set tracing"
+        fi
+    fi
 
     # check that sudo calls in phases run outside the chroot look
     # "safe"; meaning that they seem to operate within the chroot
diff --git a/doc/source/developer/developing_elements.rst b/doc/source/developer/developing_elements.rst
index aa5364406..fa6c24b63 100644
--- a/doc/source/developer/developing_elements.rst
+++ b/doc/source/developer/developing_elements.rst
@@ -172,11 +172,12 @@ the image as executable files.
 Environment Variables
 ^^^^^^^^^^^^^^^^^^^^^
 
-To set environment variables for other hooks, add a file to your element
-``environment.d``.
-
-This directory contains bash script snippets that are sourced before running
-scripts in each phase.
+To set environment variables for other hooks, add a file to your
+element ``environment.d``.  This directory contains bash script
+snippets that are sourced before running scripts in each phase.  Note
+that because environment includes are sourced together, they should
+not set global flags like ``set -x`` because they will affect all
+preceeding imports.
 
 DIB exposes an internal ``$IMAGE_ELEMENT`` variable which provides elements
 access to the full set of elements that are included in the image build. This
diff --git a/elements/centos/environment.d/00-bootloader.bash b/elements/centos/environment.d/00-bootloader.bash
index 6478bc967..d406155d7 100755
--- a/elements/centos/environment.d/00-bootloader.bash
+++ b/elements/centos/environment.d/00-bootloader.bash
@@ -1,9 +1 @@
-#!/bin/bash
-
-if [ "${DIB_DEBUG_TRACE:-0}" -gt 0 ]; then
-    set -x
-fi
-set -eu
-set -o pipefail
-
 export DIB_EXTLINUX=1
diff --git a/elements/manifests/environment.d/14-manifests b/elements/manifests/environment.d/14-manifests
index c2ae96dc9..a125a6f2f 100755
--- a/elements/manifests/environment.d/14-manifests
+++ b/elements/manifests/environment.d/14-manifests
@@ -1,5 +1,3 @@
-#!/bin/bash
-#
 # Copyright 2014 Hewlett-Packard Development Company, L.P.
 #
 # Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -15,11 +13,5 @@
 # under the License.
 #
 
-if [ ${DIB_DEBUG_TRACE:-0} -gt 0 ]; then
-    set -x
-fi
-set -eu
-set -o pipefail
-
 export DIB_MANIFEST_IMAGE_DIR=${DIB_MANIFEST_IMAGE_DIR:-/etc/dib-manifests}
 export DIB_MANIFEST_SAVE_DIR=${DIB_MANIFEST_SAVE_DIR:-${IMAGE_NAME}.d/}