diff --git a/test/README b/test/README
index 10f127cb..a81808b1 100644
--- a/test/README
+++ b/test/README
@@ -137,6 +137,23 @@ detection of missing prerequisites. In the future we may treat tests
 unable to run because of missing prerequisites, but not explicitly
 skipped by the user, as failures.
 
+Testing installed notmuch
+-------------------------
+
+Systems integrators (e.g. Linux distros) may wish to test an installed
+version of notmuch.  This can be done be running
+
+     $ NOTMUCH_TEST_INSTALLED=1 ./test/notmuch-test
+
+In this scenario the test suite does not assume a built tree, and in
+particular cannot rely on the output of 'configure'. You may want to
+set certain feature environment variables ('NOTMUCH_HAVE_*') directly
+if you know those apply to your installed notmuch). Consider also
+setting TERM=dumb if the value of TERM cannot be used (e.g. in a
+chroot with missing terminfo). Note that having a built tree may cause
+surprising/broken results for NOTMUCH_TEST_INSTALLED, so consider
+cleaning first.
+
 Writing Tests
 -------------
 The test script is written as a shell script. It is to be named as
diff --git a/test/T000-basic.sh b/test/T000-basic.sh
index a2f4d93f..642f918d 100755
--- a/test/T000-basic.sh
+++ b/test/T000-basic.sh
@@ -66,6 +66,7 @@ test_begin_subtest 'NOTMUCH_CONFIG is set and points to an existing file'
 test_expect_success 'test -f "${NOTMUCH_CONFIG}"'
 
 test_begin_subtest 'PATH is set to build directory'
+test_subtest_broken_for_installed
 test_expect_equal \
     "$(dirname ${TEST_DIRECTORY})" \
     "$(echo $PATH|cut -f1 -d: | sed -e 's,/test/valgrind/bin$,,')"
diff --git a/test/T010-help-test.sh b/test/T010-help-test.sh
index 1fbc46a2..827edc14 100755
--- a/test/T010-help-test.sh
+++ b/test/T010-help-test.sh
@@ -19,6 +19,9 @@ if [ "${NOTMUCH_HAVE_MAN-0}" = "1" ]; then
     test_begin_subtest 'notmuch help tag'
     test_expect_success 'notmuch help tag'
 else
+    if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+	test_done
+    fi
     test_begin_subtest 'notmuch --help tag (man pages not available)'
     test_expect_success 'test_must_fail notmuch --help tag >/dev/null'
 
diff --git a/test/T160-json.sh b/test/T160-json.sh
index f61c3f2d..318c9788 100755
--- a/test/T160-json.sh
+++ b/test/T160-json.sh
@@ -65,6 +65,7 @@ test_expect_equal_json "$output" "[{\"thread\": \"XXX\",
  \"tags\": [\"inbox\",
  \"unread\"]}]"
 
+if [ -z "${NOTMUCH_TEST_INSTALLED-}" ]; then
 test_begin_subtest "Search message: json, 64-bit timestamp"
 if [ "${NOTMUCH_HAVE_64BIT_TIME_T-0}" != "1" ]; then
     test_subtest_known_broken
@@ -81,6 +82,7 @@ test_expect_equal_json "$output" "[{\"thread\": \"XXX\",
  \"query\": [\"id:$gen_msg_id\", null],
  \"tags\": [\"inbox\",
  \"unread\"]}]"
+fi # NOTMUCH_TEST_INSTALLED undefined / empty
 
 test_begin_subtest "Format version: too low"
 test_expect_code 20 "notmuch search --format-version=0 \\*"
diff --git a/test/T240-dump-restore.sh b/test/T240-dump-restore.sh
index 80939030..c3f18839 100755
--- a/test/T240-dump-restore.sh
+++ b/test/T240-dump-restore.sh
@@ -139,6 +139,7 @@ notmuch dump --output=dump-outfile-dash-inbox.actual -- from:cworth
 test_expect_equal_file dump-cworth.expected dump-outfile-dash-inbox.actual
 
 test_begin_subtest "Check for a safe set of message-ids"
+test_subtest_broken_for_installed
 notmuch search --output=messages from:cworth | sed s/^id:// > EXPECTED
 notmuch search --output=messages from:cworth | sed s/^id:// |\
 	$TEST_DIRECTORY/hex-xcode --direction=encode > OUTPUT
@@ -246,6 +247,7 @@ notmuch dump --format=batch-tag > OUTPUT.$test_count
 test_expect_equal_file EXPECTED.$test_count OUTPUT.$test_count
 
 test_begin_subtest 'format=batch-tag, checking encoded output'
+test_subtest_broken_for_installed
 NOTMUCH_DUMP_TAGS --format=batch-tag -- from:cworth |\
 	 awk "{ print \"+$enc1 +$enc2 +$enc3 -- \" \$5 }" > EXPECTED.$test_count
 NOTMUCH_DUMP_TAGS --format=batch-tag -- from:cworth > OUTPUT.$test_count
diff --git a/test/T310-emacs.sh b/test/T310-emacs.sh
index 9d0df187..d3aa2e7d 100755
--- a/test/T310-emacs.sh
+++ b/test/T310-emacs.sh
@@ -258,6 +258,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "Verify that sent messages are saved/searchable (via FCC)"
+test_subtest_broken_for_installed
 notmuch new > /dev/null
 output=$(notmuch search 'subject:"testing message sent via SMTP"' | notmuch_search_sanitize)
 test_expect_equal "$output" "thread:XXX   2000-01-01 [1/1] Notmuch Test Suite; Testing message sent via SMTP (inbox)"
@@ -350,6 +351,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "Reply within emacs"
+test_subtest_broken_for_installed
 test_emacs '(let ((message-hidden-headers ''()))
 	    (notmuch-search "subject:\"testing message sent via SMTP\"")
 	    (notmuch-test-wait)
diff --git a/test/T350-crypto.sh b/test/T350-crypto.sh
index 721cbfdd..27c0e86d 100755
--- a/test/T350-crypto.sh
+++ b/test/T350-crypto.sh
@@ -30,6 +30,7 @@ msg_file=$(notmuch search --output=files subject:signed-message-sent-via-SMTP)
 test_expect_equal_message_body sent_message "$msg_file"
 
 test_begin_subtest "signed part content-type indexing"
+test_subtest_broken_for_installed
 notmuch search mimetype:multipart/signed and mimetype:application/pgp-signature | notmuch_search_sanitize > OUTPUT
 cat <<EOF >EXPECTED
 thread:XXX   2000-01-01 [1/1] Notmuch Test Suite; test signed message 001 (inbox signed)
diff --git a/test/T355-smime.sh b/test/T355-smime.sh
index 3bd5a17e..d2118c04 100755
--- a/test/T355-smime.sh
+++ b/test/T355-smime.sh
@@ -183,6 +183,7 @@ test_begin_subtest "show PKCS#7 SignedData outputs valid JSON"
 output=$(notmuch show --format=json id:smime-onepart-signed@protected-headers.example)
 test_valid_json "$output"
 
+if [ -z "${NOTMUCH_TEST_INSTALLED-}" ]; then
 test_begin_subtest "Verify signature on PKCS#7 SignedData message"
 if [ "${NOTMUCH_HAVE_64BIT_TIME_T-0}" != "1" ]; then
     test_subtest_known_broken
@@ -194,6 +195,7 @@ test_json_nodes <<<"$output" \
                 'expires:[0][0][0]["crypto"]["signed"]["status"][0]["expires"]=2611032858' \
                 'fingerprint:[0][0][0]["crypto"]["signed"]["status"][0]["fingerprint"]="702BA4B157F1E2B7D16B0C6A5FFC8A7DE2057DEB"' \
                 'status:[0][0][0]["crypto"]["signed"]["status"][0]["status"]="good"'
+fi # NOTMUCH_TEST_INSTALLED undefined / empty
 
 test_begin_subtest "Verify signature on PKCS#7 SignedData message signer User ID"
 if [ $NOTMUCH_GMIME_X509_CERT_VALIDITY -ne 1 ]; then
diff --git a/test/T360-symbol-hiding.sh b/test/T360-symbol-hiding.sh
index 642457bf..ff06ff69 100755
--- a/test/T360-symbol-hiding.sh
+++ b/test/T360-symbol-hiding.sh
@@ -11,6 +11,10 @@ test_description='exception symbol hiding'
 
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 test_begin_subtest 'running test' run_test
 mkdir -p ${PWD}/fakedb/.notmuch
 $TEST_DIRECTORY/symbol-test ${PWD}/fakedb ${PWD}/nonexistent 2>&1 \
diff --git a/test/T390-python.sh b/test/T390-python.sh
index 9f71ce3c..21912431 100755
--- a/test/T390-python.sh
+++ b/test/T390-python.sh
@@ -4,6 +4,10 @@ test_description="python bindings"
 
 test_require_external_prereq ${NOTMUCH_PYTHON}
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 add_email_corpus
 add_gnupg_home
 
diff --git a/test/T391-python-cffi.sh b/test/T391-python-cffi.sh
index 0ef9e0d3..0059b050 100755
--- a/test/T391-python-cffi.sh
+++ b/test/T391-python-cffi.sh
@@ -2,6 +2,10 @@
 test_description="python bindings (pytest)"
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 if [ "${NOTMUCH_HAVE_PYTHON3_CFFI-0}" = "0" -o "${NOTMUCH_HAVE_PYTHON3_PYTEST-0}" = "0" ]; then
     test_done
 fi
diff --git a/test/T395-ruby.sh b/test/T395-ruby.sh
index c066c842..d0c6bb17 100755
--- a/test/T395-ruby.sh
+++ b/test/T395-ruby.sh
@@ -2,7 +2,7 @@
 test_description="ruby bindings"
 . $(dirname "$0")/test-lib.sh || exit 1
 
-if [ "${NOTMUCH_HAVE_RUBY_DEV}" = "0" ]; then
+if [ -z "${NOTMUCH_TEST_INSTALLED-}" -a "${NOTMUCH_HAVE_RUBY_DEV-0}" = "0" ]; then
     test_subtest_missing_external_prereq_["ruby development files"]=t
 fi
 
@@ -15,7 +15,11 @@ test_ruby() {
 	db = Notmuch::Database.new()
 	EOF
 	cat
-    ) | $NOTMUCH_RUBY -I "$NOTMUCH_BUILDDIR/bindings/ruby"> OUTPUT
+    ) | if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+	ruby
+    else
+	$NOTMUCH_RUBY -I "$NOTMUCH_BUILDDIR/bindings/ruby"
+    fi> OUTPUT
     test_expect_equal_file EXPECTED OUTPUT
 }
 
diff --git a/test/T410-argument-parsing.sh b/test/T410-argument-parsing.sh
index d9aa8e2d..40b625fe 100755
--- a/test/T410-argument-parsing.sh
+++ b/test/T410-argument-parsing.sh
@@ -2,6 +2,10 @@
 test_description="argument parsing"
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 test_begin_subtest "sanity check"
 $TEST_DIRECTORY/arg-test pos1 --keyword=one --boolean --string=foo pos2 --int=7 --flag=one --flag=three > OUTPUT
 cat <<EOF > EXPECTED
diff --git a/test/T480-hex-escaping.sh b/test/T480-hex-escaping.sh
index b2eb80b9..8bddf3e7 100755
--- a/test/T480-hex-escaping.sh
+++ b/test/T480-hex-escaping.sh
@@ -2,6 +2,10 @@
 test_description="hex encoding and decoding"
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 test_begin_subtest "round trip"
 find $NOTMUCH_SRCDIR/test/corpora/default -type f -print | sort | xargs cat > EXPECTED
 $TEST_DIRECTORY/hex-xcode --direction=encode < EXPECTED | $TEST_DIRECTORY/hex-xcode --direction=decode > OUTPUT
diff --git a/test/T490-parse-time-string.sh b/test/T490-parse-time-string.sh
index f89755ed..3b6e48c4 100755
--- a/test/T490-parse-time-string.sh
+++ b/test/T490-parse-time-string.sh
@@ -2,6 +2,10 @@
 test_description="date/time parser module"
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 # Sanity/smoke tests for the date/time parser independent of notmuch
 
 _date () {
diff --git a/test/T550-db-features.sh b/test/T550-db-features.sh
index 9d5a9e70..3048c7c4 100755
--- a/test/T550-db-features.sh
+++ b/test/T550-db-features.sh
@@ -3,6 +3,10 @@ test_description="database version and feature compatibility"
 
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 test_begin_subtest "future database versions abort open"
 ${TEST_DIRECTORY}/make-db-version ${MAIL_DIR} 9999 ""
 output=$(notmuch search x 2>&1 | sed 's/\(database at\) .*/\1 FILENAME/')
diff --git a/test/T566-lib-message.sh b/test/T566-lib-message.sh
index 7f0e8eb0..69051937 100755
--- a/test/T566-lib-message.sh
+++ b/test/T566-lib-message.sh
@@ -3,6 +3,10 @@ test_description="API tests for notmuch_message_*"
 
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED}" ]; then
+    test_done
+fi
+
 add_email_corpus
 
 test_begin_subtest "building database"
diff --git a/test/T592-thread-breakage.sh b/test/T592-thread-breakage.sh
index 92a70e3e..2334fcaf 100755
--- a/test/T592-thread-breakage.sh
+++ b/test/T592-thread-breakage.sh
@@ -21,6 +21,10 @@ test_description='thread breakage during reindexing'
 
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 message_a () {
     mkdir -p ${MAIL_DIR}/cur
     cat > ${MAIL_DIR}/cur/a <<EOF
diff --git a/test/T710-message-id.sh b/test/T710-message-id.sh
index 5129d84c..a2d8ec71 100755
--- a/test/T710-message-id.sh
+++ b/test/T710-message-id.sh
@@ -3,6 +3,10 @@ test_description="message id parsing"
 
 . $(dirname "$0")/test-lib.sh || exit 1
 
+if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    test_done
+fi
+
 test_begin_subtest "good message ids"
 ${TEST_DIRECTORY}/message-id-parse <<EOF >OUTPUT
 <018b1a8f2d1df62e804ce88b65401304832dfbbf.1346614915.git.jani@nikula.org>
diff --git a/test/T800-asan.sh b/test/T800-asan.sh
index 7c28dc7c..9ce6baa7 100755
--- a/test/T800-asan.sh
+++ b/test/T800-asan.sh
@@ -7,6 +7,11 @@ if [ "${NOTMUCH_HAVE_ASAN-0}" != "1" ]; then
     test_done
 fi
 
+if [ -n "${LD_PRELOAD-}" ]; then
+    printf "Skipping due to ASAN LD_PRELOAD restrictions\n"
+    test_done
+fi
+
 add_email_corpus
 
 TEST_CFLAGS="${TEST_CFLAGS:-} -fsanitize=address"
diff --git a/test/T850-git.sh b/test/T850-git.sh
index be6e0cd4..831e4678 100755
--- a/test/T850-git.sh
+++ b/test/T850-git.sh
@@ -233,6 +233,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "invoke as nmbug sets defaults"
+test_subtest_broken_for_installed
 "$NOTMUCH_BUILDDIR"/nmbug -ldebug status |& grep '^\(prefix\|repository\)' | notmuch_dir_sanitize > OUTPUT
 cat <<EOF > EXPECTED
 prefix = notmuch::
@@ -241,6 +242,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "env variable NOTMUCH_GIT_DIR works when invoked as nmbug"
+test_subtest_broken_for_installed
 NOTMUCH_GIT_DIR=`pwd`/foo "$NOTMUCH_BUILDDIR"/nmbug -ldebug status |& grep '^repository' | notmuch_dir_sanitize > OUTPUT
 cat <<EOF > EXPECTED
 repository = CWD/foo
@@ -256,6 +258,7 @@ test_expect_equal_file EXPECTED OUTPUT
 
 
 test_begin_subtest "env variable NOTMUCH_GIT_DIR overrides config when invoked as 'nmbug'"
+test_subtest_broken_for_installed
 notmuch config set git.path `pwd`/bar
 NOTMUCH_GIT_DIR=`pwd`/remote.git  "$NOTMUCH_BUILDDIR"/nmbug -ldebug status |& grep '^repository' | notmuch_dir_sanitize > OUTPUT
 notmuch config set git.path
@@ -274,6 +277,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "env variable NOTMUCH_GIT_PREFIX works when invoked as 'nmbug'"
+test_subtest_broken_for_installed
 NOTMUCH_GIT_PREFIX=env:: "$NOTMUCH_BUILDDIR"/nmbug -ldebug status |& grep '^prefix' | notmuch_dir_sanitize > OUTPUT
 cat <<EOF > EXPECTED
 prefix = env::
@@ -281,6 +285,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "env variable NOTMUCH_GIT_PREFIX works when invoked as nmbug"
+test_subtest_broken_for_installed
 NOTMUCH_GIT_PREFIX=foo:: "$NOTMUCH_BUILDDIR"/nmbug -ldebug status |& grep '^prefix' | notmuch_dir_sanitize > OUTPUT
 cat <<EOF > EXPECTED
 prefix = foo::
@@ -288,6 +293,7 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "env variable NOTMUCH_GIT_PREFIX overrides config when invoked as 'nmbug'"
+test_subtest_broken_for_installed
 notmuch config set git.tag_prefix config::
 NOTMUCH_GIT_PREFIX=env:: "$NOTMUCH_BUILDDIR"/nmbug -ldebug status |& grep '^prefix' | notmuch_dir_sanitize > OUTPUT
 notmuch config set git.path
diff --git a/test/export-dirs.sh b/test/export-dirs.sh
index 0a048e1f..9bc99a2c 100644
--- a/test/export-dirs.sh
+++ b/test/export-dirs.sh
@@ -24,7 +24,7 @@ find_builddir () {
 if [[ -z "${NOTMUCH_BUILDDIR}" ]]; then
 	export NOTMUCH_BUILDDIR="$(find_builddir "$(pwd)")"
 
-	if [[ -z "${NOTMUCH_BUILDDIR}" ]]; then
+	if [ -z "${NOTMUCH_BUILDDIR}" -a "${NOTMUCH_TEST_INSTALLED-0}" = "0" ]; then
 		echo "Run tests in a subdir of built notmuch tree." >&2
 		exit 1
 	fi
diff --git a/test/notmuch-test b/test/notmuch-test
index 14747bdb..5d27e4d1 100755
--- a/test/notmuch-test
+++ b/test/notmuch-test
@@ -20,6 +20,14 @@ fi
 
 set -eu
 
+# Where to run the tests
+# XXX FIXME this code is duplicated with test-lib.sh
+if [[ -n "${NOTMUCH_BUILDDIR}" ]]; then
+    TEST_DIRECTORY=$NOTMUCH_BUILDDIR/test
+else
+    TEST_DIRECTORY=$NOTMUCH_SRCDIR/test
+fi
+
 TESTS=
 for test in ${NOTMUCH_TESTS-}; do
     TESTS="$TESTS $NOTMUCH_SRCDIR/test/$test"
@@ -80,7 +88,7 @@ for file in $TESTS
 do
     file=${file##*/} # drop leading path components
     file=${file%.sh} # drop trailing '.sh'
-    RESULT_FILES="$RESULT_FILES $NOTMUCH_BUILDDIR/test/test-results/$file"
+    RESULT_FILES="$RESULT_FILES $TEST_DIRECTORY/test-results/$file"
 done
 
 echo
@@ -94,6 +102,6 @@ if [ -n "$META_FAILURE" ]; then
 fi
 
 # Clean up
-rm -rf $NOTMUCH_BUILDDIR/test/test-results
+rm -rf $TEST_DIRECTORY/test-results
 
 exit $ev
diff --git a/test/test-lib-common.sh b/test/test-lib-common.sh
index 4d14e0b3..f5d72e12 100644
--- a/test/test-lib-common.sh
+++ b/test/test-lib-common.sh
@@ -24,7 +24,7 @@
 #
 type die >/dev/null 2>&1 || die () { echo "$@" >&2; exit 1; }
 
-if [[ -z "$NOTMUCH_SRCDIR" ]] || [[ -z "$NOTMUCH_BUILDDIR" ]]; then
+if [[ -z "$NOTMUCH_SRCDIR" ]] || [ -z "${NOTMUCH_TEST_INSTALLED-}" -a -z "$NOTMUCH_BUILDDIR" ]; then
 	echo "internal: srcdir or builddir not set" >&2
 	exit 1
 fi
@@ -61,7 +61,9 @@ LD_LIBRARY_PATH=${TEST_DIRECTORY%/*}/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
 export LD_LIBRARY_PATH
 
 # configure output
-. "$NOTMUCH_BUILDDIR/sh.config" || exit 1
+if [ -z "${NOTMUCH_TEST_INSTALLED-}" ]; then
+   . "$NOTMUCH_BUILDDIR/sh.config" || exit 1
+fi
 
 # load OS specifics
 if [[ -e "$NOTMUCH_SRCDIR/test/test-lib-$PLATFORM.sh" ]]; then
@@ -315,7 +317,12 @@ export PATH MANPATH
 
 # Test repository
 test="tmp.$(basename "$0" .sh)"
-TMP_DIRECTORY="$TEST_DIRECTORY/$test"
+if [ -z "${NOTMUCH_TEST_INSTALLED-}" ]; then
+    TMP_DIRECTORY="$TEST_DIRECTORY/$test"
+else
+    TMP_DIRECTORY=$(mktemp -d "${TMPDIR:-/tmp}/notmuch-$test.XXXXXX")
+fi
+
 test ! -z "$debug" || remove_tmp=$TMP_DIRECTORY
 rm -rf "$TMP_DIRECTORY" || {
 	GIT_EXIT_OK=t
diff --git a/test/test-lib-emacs.sh b/test/test-lib-emacs.sh
index ad4c4aeb..0ab58fc2 100644
--- a/test/test-lib-emacs.sh
+++ b/test/test-lib-emacs.sh
@@ -30,6 +30,7 @@ test_require_emacs () {
 # to the message and encrypting/signing.
 emacs_deliver_message () {
     local subject body smtp_dummy_pid smtp_dummy_port
+    test_subtest_broken_for_installed
     subject="$1"
     body="$2"
     shift 2
@@ -144,6 +145,13 @@ emacs_generate_script () {
 	# Construct a little test script here for the benefit of the user,
 	# (who can easily run "run_emacs" to get the same emacs environment
 	# for investigating any failures).
+    if [ -z "${NOTMUCH_TEST_INSTALLED-}" ]; then
+	find_notmuch_el='--directory "$NOTMUCH_BUILDDIR/emacs"'
+    else
+	### XXX FIXME: this should really use the installed emacs lisp files
+	find_notmuch_el='--directory "$NOTMUCH_SRCDIR/emacs"'
+    fi
+
 	cat <<EOF >"$TMP_DIRECTORY/run_emacs"
 #!/bin/sh
 export PATH=$PATH
@@ -158,8 +166,8 @@ export NOTMUCH_CONFIG=$NOTMUCH_CONFIG
 #
 # --load		Force loading of notmuch.el and test-lib.el
 
-exec ${TEST_EMACS} --quick \
-	--directory "$NOTMUCH_BUILDDIR/emacs" --load notmuch.el \
+exec ${TEST_EMACS} ${find_notmuch_el} --quick \
+	${EXTRA_DIR} --load notmuch.el \
 	--directory "$NOTMUCH_SRCDIR/test" --load test-lib.el \
 	"\$@"
 EOF
diff --git a/test/test-lib.sh b/test/test-lib.sh
index f218fa03..059e110c 100644
--- a/test/test-lib.sh
+++ b/test/test-lib.sh
@@ -29,8 +29,8 @@ shopt -u xpg_echo
 # Ensure NOTMUCH_SRCDIR and NOTMUCH_BUILDDIR are set.
 . $(dirname "$0")/export-dirs.sh || exit 1
 
-# It appears that people try to run tests without building...
-if [[ ! -x "$NOTMUCH_BUILDDIR/notmuch" ]]; then
+# We need either a built tree, or a promise of an installed notmuch
+if [ -z "${NOTMUCH_TEST_INSTALLED-}" -a ! -x "$NOTMUCH_BUILDDIR/notmuch" ]; then
 	echo >&2 'You do not seem to have built notmuch yet.'
 	exit 1
 fi
@@ -748,6 +748,12 @@ test_subtest_known_broken () {
 	test_subtest_known_broken_=t
 }
 
+test_subtest_broken_for_installed () {
+    if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+	test_subtest_known_broken_=t
+    fi
+}
+
 test_subtest_broken_for_root () {
    if [ "$EUID" = "0" ]; then
 	test_subtest_known_broken_=t
@@ -929,11 +935,16 @@ make_shim () {
 }
 
 notmuch_with_shim () {
-    local base_name shim_file
-    base_name="$1"
+    local base_name shim_file notmuch_cmd
+    if [ -n "${NOTMUCH_TEST_INSTALLED-}" ]; then
+	notmuch_cmd="notmuch"
+    else
+	notmuch_cmd="notmuch-shared"
+    fi
+    base_name=$1
     shift
     shim_file="${base_name}.so"
-    LD_PRELOAD=${LD_PRELOAD:+:$LD_PRELOAD}:./${shim_file} notmuch-shared "$@"
+    LD_PRELOAD=${LD_PRELOAD:+:$LD_PRELOAD}:./${shim_file} $notmuch_cmd "$@"
 }
 
 # Creates a script that counts how much time it is executed and calls
@@ -985,7 +996,11 @@ test_init_ () {
 
 
 # Where to run the tests
-TEST_DIRECTORY=$NOTMUCH_BUILDDIR/test
+if [[ -n "${NOTMUCH_BUILDDIR}" ]]; then
+    TEST_DIRECTORY=$NOTMUCH_BUILDDIR/test
+else
+    TEST_DIRECTORY=$NOTMUCH_SRCDIR/test
+fi
 
 . "$NOTMUCH_SRCDIR/test/test-lib-common.sh" || exit 1