diff --git a/subprojects/wren/find_scripts.py b/subprojects/wren/find_scripts.py
index eb0fc72..cf28a26 100755
--- a/subprojects/wren/find_scripts.py
+++ b/subprojects/wren/find_scripts.py
@@ -2,11 +2,16 @@
 
 from pathlib import Path
 import sys
+import os
 
-if len(sys.argv) < 2:
-    sys.stderr.write("Please specify a search directory\n")
+if len(sys.argv) < 3:
+    sys.stderr.write("Usage: {0} <prefix> <paths>...\n".format(sys.argv[0]))
     exit(2)
 
-for search_path in sys.argv[1:]:
-    for path in Path(search_path).rglob('*.wren'):
+prefix = sys.argv[1]
+search_paths = sys.argv[2:]
+
+for search_path in search_paths:
+    curr_path = os.path.join(prefix, search_path)
+    for path in Path(curr_path).rglob('*.wren'):
         sys.stdout.write(str(path) + "\n")
diff --git a/subprojects/wren/guess_test_outcome.py b/subprojects/wren/guess_test_outcome.py
new file mode 100755
index 0000000..48386b7
--- /dev/null
+++ b/subprojects/wren/guess_test_outcome.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+
+import sys
+import re
+
+if len(sys.argv) != 2:
+    sys.stderr.write("Please specify a file path\n")
+    exit(2)
+
+try:
+    my_file = open(sys.argv[1], mode='r')
+    text = my_file.read()
+    my_file.close()
+except UnicodeDecodeError:
+    exit(0)
+
+if re.search(r"expect\s+(?:runtime\s+)?\berror", text):
+    exit(0)
+else:
+    exit(1)
diff --git a/subprojects/wren/meson.build b/subprojects/wren/meson.build
index b356d86..48c7f46 100644
--- a/subprojects/wren/meson.build
+++ b/subprojects/wren/meson.build
@@ -67,6 +67,7 @@ wren_dep = declare_dependency(
 
 if get_option('build_testing')
   fs = import('fs')
+
   test_src = [
 	'wren/test/api/api_tests.c',
 	'wren/test/api/benchmark.c',
@@ -101,8 +102,8 @@ if get_option('build_testing')
   endif
 
   test_scripts = run_command(
-	meson.current_source_dir() / 'find_scripts.py',
-	meson.current_source_dir(),
+	files('find_scripts.py'),
+	meson.current_source_dir() / 'wren/test',
 	test_script_paths,
   ).stdout().strip().split('\n')
 
@@ -115,8 +116,20 @@ if get_option('build_testing')
   )
 
   foreach test_script : test_scripts
+	expects_fail = run_command(
+	  files('guess_test_outcome.py'),
+	  test_script,
+	).returncode() == 0
+
 	name = fs.stem(test_script)
-	test(meson.project_name() + ' test ' + name, test_api, args: files(test_script))
+	test(
+	  meson.project_name() + ' test ' + name,
+	  test_api,
+	  args: test_script,
+	  is_parallel: true,
+	  should_fail: expects_fail,
+	  workdir: meson.current_source_dir() / 'wren',
+	)
   endforeach
 endif