--- a/installed-tests/js/meson.build
+++ b/installed-tests/js/meson.build
@@ -10,7 +10,7 @@ jsunit_resources_files = gnome.compile_resources('jsunit-resources',
 minijasmine = executable('minijasmine', '../minijasmine.cpp',
     jsunit_resources_files, dependencies: libgjs_dep,
     cpp_args: [
-        '-DINSTTESTDIR="@0@"'.format(prefix / installed_tests_execdir),
+        '-DINSTTESTDIR="@0@"'.format(installed_tests_execdir),
     ],
     include_directories: top_include,
     install: get_option('installed_tests'), install_dir: installed_tests_execdir)
@@ -90,7 +90,7 @@ foreach test : jasmine_tests
 
     test_description_subst = {
         'name': 'test@0@.js'.format(test),
-        'installed_tests_execdir': prefix / installed_tests_execdir,
+        'installed_tests_execdir': installed_tests_execdir,
     }
     configure_file(configuration: test_description_subst,
         input: '../minijasmine.test.in',
@@ -122,7 +122,7 @@ endif
 
 dbus_test_description_subst = {
     'name': 'testGDBus.js',
-    'installed_tests_execdir': prefix / installed_tests_execdir,
+    'installed_tests_execdir': installed_tests_execdir,
 }
 configure_file(
     configuration: dbus_test_description_subst,
@@ -166,7 +166,7 @@ foreach test : modules_tests
 
     esm_test_description_subst = {
         'name': 'test@0@.js'.format(test),
-        'installed_tests_execdir': prefix / installed_tests_execdir,
+        'installed_tests_execdir': installed_tests_execdir,
     }
     configure_file(configuration: esm_test_description_subst,
         input: '../minijasmine-legacy-importer.test.in',
--- a/installed-tests/meson.build
+++ b/installed-tests/meson.build
@@ -34,7 +34,7 @@ foreach test : simple_tests
 
     test_description_subst = {
         'name': 'test@0@.sh'.format(test),
-        'installed_tests_execdir': prefix / installed_tests_execdir,
+        'installed_tests_execdir': installed_tests_execdir,
     }
     configure_file(configuration: test_description_subst,
         input: 'script.test.in', output: 'test@0@.sh.test'.format(test),
@@ -88,7 +88,7 @@ foreach test : debugger_tests
 
     test_description_subst = {
         'name': '@0@.debugger'.format(test),
-        'installed_tests_execdir': prefix / installed_tests_execdir,
+        'installed_tests_execdir': installed_tests_execdir,
     }
     configure_file(configuration: test_description_subst,
         input: 'debugger.test.in',
@@ -122,7 +122,7 @@ foreach test : module_debugger_tests
 
     test_description_subst = {
         'name': '@0@.debugger'.format(filename),
-        'installed_tests_execdir': prefix / installed_tests_execdir,
+        'installed_tests_execdir': installed_tests_execdir,
     }
     configure_file(configuration: test_description_subst,
         input: 'debugger.test.in',
--- a/meson.build
+++ b/meson.build
@@ -25,8 +25,8 @@ datadir = get_option('datadir')
 libexecdir = get_option('libexecdir')
 gjsjsdir = datadir / api_name
 pkglibdir = libdir / meson.project_name()
-installed_tests_execdir = libexecdir / 'installed-tests' / meson.project_name()
-installed_tests_metadir = datadir / 'installed-tests' / meson.project_name()
+installed_tests_execdir = get_option('installed_test_prefix') / libexecdir / 'installed-tests' / meson.project_name()
+installed_tests_metadir = get_option('installed_test_prefix') / datadir / 'installed-tests' / meson.project_name()
 
 ### Check for conflicting build options ########################################
 
@@ -605,9 +605,9 @@ install_data('installed-tests/extra/gjs.supp', install_dir: gjsjsdir / 'valgrind
 install_data('installed-tests/extra/lsan.supp', install_dir: gjsjsdir / 'lsan')
 
 if get_option('installed_tests')
-    schemadir = datadir / 'glib-2.0' / 'schemas'
+    schemadir = get_option('installed_test_prefix') / datadir / 'glib-2.0' / 'schemas'
     install_data('installed-tests/js/org.gnome.GjsTest.gschema.xml', install_dir: schemadir)
-    meson.add_install_script(glib_compile_schemas, prefix / schemadir, skip_if_destdir: true)
+    meson.add_install_script(glib_compile_schemas, schemadir, skip_if_destdir: true)
 endif
 
 ### Generate pkg-config file ###################################################
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -24,3 +24,5 @@ option('skip_gtk_tests', type: 'boolean', value: false,
     description: 'Skip tests that need a display connection')
 option('verbose_logs', type: 'boolean', value: false,
     description: 'Enable extra log messages that may decrease performance (not allowed in release builds)')
+option('installed_test_prefix', type: 'string', value: '',
+    description: 'Prefix for installed tests')