diff --git a/tests/cli-tests.sh b/tests/cli-tests.sh
index e65e7f50..72f7865a 100755
--- a/tests/cli-tests.sh
+++ b/tests/cli-tests.sh
@@ -2,8 +2,6 @@
 #
 # command line interface coverage tests
 
-unset TOP
-unset LANG
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f $0))
 TOP=$(readlink -f $SCRIPT_DIR/../)
@@ -17,6 +15,7 @@ export TOP
 export RESULTS
 export LANG
 export IMAGE
+export TEST_DEV
 
 rm -f $RESULTS
 
diff --git a/tests/convert-tests.sh b/tests/convert-tests.sh
index c0080b93..064540f1 100755
--- a/tests/convert-tests.sh
+++ b/tests/convert-tests.sh
@@ -2,10 +2,7 @@
 #
 # convert ext2/3/4 images to btrfs images, and make sure the results are
 # clean.
-#
 
-unset TOP
-unset LANG
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f $0))
 TOP=$(readlink -f $SCRIPT_DIR/../)
@@ -16,10 +13,11 @@ IMAGE="$TOP/tests/test.img"
 source $TOP/tests/common
 source $TOP/tests/common.convert
 
-# Allow child test to use $TOP and $RESULTS
 export TOP
 export RESULTS
 export LANG
+export IMAGE
+export TEST_DEV
 
 rm -f $RESULTS
 
diff --git a/tests/fsck-tests.sh b/tests/fsck-tests.sh
index fb861635..d1cd7329 100755
--- a/tests/fsck-tests.sh
+++ b/tests/fsck-tests.sh
@@ -1,25 +1,21 @@
 #!/bin/bash
 #
 # loop through all of our bad images and make sure fsck repairs them properly
-#
-# It's GPL, same as everything else in this tree.
-#
 
-unset TOP
-unset LANG
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f $0))
 TOP=$(readlink -f $SCRIPT_DIR/../)
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TOP/tests/fsck-tests-results.txt"
+IMAGE="$TOP/tests/test.img"
 
 source $TOP/tests/common
 
-# Allow child test to use $TOP and $RESULTS
 export TOP
 export RESULTS
-# For custom script needs to verify recovery
 export LANG
+export IMAGE
+export TEST_DEV
 
 rm -f $RESULTS
 
diff --git a/tests/fuzz-tests.sh b/tests/fuzz-tests.sh
index 204dce2d..29691cae 100755
--- a/tests/fuzz-tests.sh
+++ b/tests/fuzz-tests.sh
@@ -2,8 +2,6 @@
 #
 # misc tests on fuzzed or crafted images
 
-unset TOP
-unset LANG
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f $0))
 TOP=$(readlink -f $SCRIPT_DIR/../)
@@ -17,6 +15,7 @@ export TOP
 export RESULTS
 export LANG
 export IMAGE
+export TEST_DEV
 
 rm -f $RESULTS
 
diff --git a/tests/misc-tests.sh b/tests/misc-tests.sh
index 0cf8c4b2..eefe8a81 100755
--- a/tests/misc-tests.sh
+++ b/tests/misc-tests.sh
@@ -2,8 +2,6 @@
 #
 # Misc tests
 
-unset TOP
-unset LANG
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f $0))
 TOP=$(readlink -f $SCRIPT_DIR/../)
@@ -13,12 +11,10 @@ IMAGE="$TOP/tests/test.img"
 
 source $TOP/tests/common
 
-# Allow child test to use $TOP and $RESULTS
 export TOP
 export RESULTS
-# For custom script needs to verify recovery
 export LANG
-# For tests that only use a loop device
+export TEST_DEV
 export IMAGE
 
 rm -f $RESULTS
diff --git a/tests/mkfs-tests.sh b/tests/mkfs-tests.sh
index 363a865e..1afc0282 100755
--- a/tests/mkfs-tests.sh
+++ b/tests/mkfs-tests.sh
@@ -2,8 +2,6 @@
 #
 # mkfs.btrfs tests
 
-unset TOP
-unset LANG
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f $0))
 TOP=$(readlink -f $SCRIPT_DIR/../)
@@ -13,13 +11,11 @@ IMAGE="$TOP/tests/test.img"
 
 source $TOP/tests/common
 
-# Allow child test to use $TOP and $RESULTS
 export TOP
 export RESULTS
-# For custom script needs to verify recovery
 export LANG
-# For tests that only use a loop device
 export IMAGE
+export TEST_DEV
 
 rm -f $RESULTS