diff --git a/tests/clean-tests.sh b/tests/clean-tests.sh
index 61baa069..f5f63092 100755
--- a/tests/clean-tests.sh
+++ b/tests/clean-tests.sh
@@ -1,9 +1,34 @@
 #!/bin/bash
 # remove all intermediate files from tests
 
+LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-source "$TOP/tests/common"
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
+fi
+TEST_DEV=${TEST_DEV:-}
+RESULTS="$TEST_TOP/cli-tests-results.txt"
+IMAGE="$TEST_TOP/test.img"
+
+source "$TEST_TOP/tests/common"
 
 setup_root_helper
 
diff --git a/tests/cli-tests.sh b/tests/cli-tests.sh
index b981f833..9e0fbae4 100755
--- a/tests/cli-tests.sh
+++ b/tests/cli-tests.sh
@@ -4,10 +4,26 @@
 
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-TEST_TOP=$(readlink -f "$SCRIPT_DIR/../tests/")
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-if ! [ -f "$TOP/btrfs" ];then
-	TOP=$(dirname `which btrfs`)
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
 fi
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TEST_TOP/cli-tests-results.txt"
@@ -15,6 +31,7 @@ IMAGE="$TEST_TOP/test.img"
 
 source "$TEST_TOP/common"
 
+export INTERNAL_BIN
 export TEST_TOP
 export TOP
 export RESULTS
diff --git a/tests/convert-tests.sh b/tests/convert-tests.sh
index 52c59d4d..4bc915db 100755
--- a/tests/convert-tests.sh
+++ b/tests/convert-tests.sh
@@ -5,10 +5,26 @@
 
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-TEST_TOP=$(readlink -f "$SCRIPT_DIR/../tests/")
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-if ! [ -f "$TOP/btrfs" ];then
-	TOP=$(dirname `which btrfs`)
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
 fi
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TEST_TOP/convert-tests-results.txt"
@@ -17,6 +33,7 @@ IMAGE="$TEST_TOP/test.img"
 source "$TEST_TOP/common"
 source "$TEST_TOP/common.convert"
 
+export INTERNAL_BIN
 export TEST_TOP
 export TOP
 export RESULTS
diff --git a/tests/fsck-tests.sh b/tests/fsck-tests.sh
index f97ae986..14287bbe 100755
--- a/tests/fsck-tests.sh
+++ b/tests/fsck-tests.sh
@@ -4,11 +4,26 @@
 
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-INTERNAL_BIN=$(readlink -f "$SCRIPT_DIR/../")
-TEST_TOP=$(readlink -f "$SCRIPT_DIR/../tests/")
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-if ! [ -f "$TOP/btrfs" ];then
-	TOP=$(dirname `which btrfs`)
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
 fi
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TEST_TOP/fsck-tests-results.txt"
diff --git a/tests/fuzz-tests.sh b/tests/fuzz-tests.sh
index dca84f10..7bc620f0 100755
--- a/tests/fuzz-tests.sh
+++ b/tests/fuzz-tests.sh
@@ -4,10 +4,26 @@
 
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-TEST_TOP=$(readlink -f "$SCRIPT_DIR/../tests/")
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-if ! [ -f "$TOP/btrfs" ];then
-	TOP=$(dirname `which btrfs`)
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
 fi
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TEST_TOP/fuzz-tests-results.txt"
@@ -15,6 +31,7 @@ IMAGE="$TEST_TOP/test.img"
 
 source "$TEST_TOP/common"
 
+export INTERNAL_BIN
 export TEST_TOP
 export TOP
 export RESULTS
diff --git a/tests/misc-tests.sh b/tests/misc-tests.sh
index fed1b36c..94703a3e 100755
--- a/tests/misc-tests.sh
+++ b/tests/misc-tests.sh
@@ -4,11 +4,26 @@
 
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-TEST_TOP=$(readlink -f "$SCRIPT_DIR/../tests/")
-INTERNAL_BIN=$(readlink -f "$SCRIPT_DIR/../")
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-if ! [ -f "$TOP/btrfs" ];then
-	TOP=$(dirname `which btrfs`)
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
 fi
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TEST_TOP/misc-tests-results.txt"
@@ -21,8 +36,8 @@ export TEST_TOP
 export TOP
 export RESULTS
 export LANG
-export TEST_DEV
 export IMAGE
+export TEST_DEV
 
 rm -f "$RESULTS"
 
diff --git a/tests/mkfs-tests.sh b/tests/mkfs-tests.sh
index 1a84b37c..2ced4ac9 100755
--- a/tests/mkfs-tests.sh
+++ b/tests/mkfs-tests.sh
@@ -4,11 +4,26 @@
 
 LANG=C
 SCRIPT_DIR=$(dirname $(readlink -f "$0"))
-INTERNAL_BIN=$(readlink -f "$SCRIPT_DIR/../")
-TEST_TOP=$(readlink -f "$SCRIPT_DIR/../tests/")
-TOP=$(readlink -f "$SCRIPT_DIR/../")
-if ! [ -f "$TOP/btrfs" ];then
-	TOP=$(dirname `which btrfs`)
+if [ -z "$TOP" ]; then
+	TOP=$(readlink -f "$SCRIPT_DIR/../")
+	if [ -f "$TOP/configure.ac" ]; then
+		# inside git
+		TEST_TOP="$TOP/tests/"
+		INTERNAL_BIN="$TOP"
+	else
+		# external, defaults to system binaries
+		TOP=$(dirname `which btrfs`)
+		TEST_TOP="$SCRIPT_DIR"
+		INTERNAL_BIN="$TEST_TOP"
+	fi
+else
+	# assume external, TOP set from commandline
+	TEST_TOP="$SCRIPT_DIR"
+	INTERNAL_BIN="$TEST_TOP"
+fi
+if ! [ -x "$TOP/btrfs" ]; then
+	echo "ERROR: cannot execute btrfs from TOP=$TOP"
+	exit 1
 fi
 TEST_DEV=${TEST_DEV:-}
 RESULTS="$TEST_TOP/mkfs-tests-results.txt"