diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 9bdda1394e..da7e8a87fe 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -26,9 +26,23 @@ from findtests import TestFinder
 from testenv import TestEnv
 from testrunner import TestRunner
 
+def get_default_path(follow_link=False):
+    """
+    Try to automagically figure out the path we are running from.
+    """
+    # called from the build tree?
+    if os.path.islink(sys.argv[0]):
+        if follow_link:
+            return os.path.dirname(os.readlink(sys.argv[0]))
+        else:
+            return os.path.dirname(os.path.abspath(sys.argv[0]))
+    else:  # or source tree?
+        return os.getcwd()
 
 def make_argparser() -> argparse.ArgumentParser:
-    p = argparse.ArgumentParser(description="Test run options")
+    p = argparse.ArgumentParser(
+        description="Test run options",
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
 
     p.add_argument('-n', '--dry-run', action='store_true',
                    help='show me, do not run tests')
@@ -113,6 +127,11 @@ def make_argparser() -> argparse.ArgumentParser:
                        'middle of the process.')
     g_sel.add_argument('tests', metavar='TEST_FILES', nargs='*',
                        help='tests to run, or "--" followed by a command')
+    g_sel.add_argument('--build-dir', default=get_default_path(),
+                       help='Path to iotests build directory')
+    g_sel.add_argument('--source-dir',
+                       default=get_default_path(follow_link=True),
+                       help='Path to iotests build directory')
 
     return p
 
@@ -120,7 +139,9 @@ def make_argparser() -> argparse.ArgumentParser:
 if __name__ == '__main__':
     args = make_argparser().parse_args()
 
-    env = TestEnv(imgfmt=args.imgfmt, imgproto=args.imgproto,
+    env = TestEnv(source_dir=args.source_dir,
+                  build_dir=args.build_dir,
+                  imgfmt=args.imgfmt, imgproto=args.imgproto,
                   aiomode=args.aiomode, cachemode=args.cachemode,
                   imgopts=args.imgopts, misalign=args.misalign,
                   debug=args.debug, valgrind=args.valgrind,
diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
index a864c74b12..aa9d735414 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -170,7 +170,8 @@ class TestEnv(ContextManager['TestEnv']):
             if not isxfile(b):
                 sys.exit('Not executable: ' + b)
 
-    def __init__(self, imgfmt: str, imgproto: str, aiomode: str,
+    def __init__(self, source_dir: str, build_dir: str,
+                 imgfmt: str, imgproto: str, aiomode: str,
                  cachemode: Optional[str] = None,
                  imgopts: Optional[str] = None,
                  misalign: bool = False,
@@ -211,14 +212,8 @@ class TestEnv(ContextManager['TestEnv']):
         # which are needed to initialize some environment variables. They are
         # used by init_*() functions as well.
 
-        if os.path.islink(sys.argv[0]):
-            # called from the build tree
-            self.source_iotests = os.path.dirname(os.readlink(sys.argv[0]))
-            self.build_iotests = os.path.dirname(os.path.abspath(sys.argv[0]))
-        else:
-            # called from the source tree
-            self.source_iotests = os.getcwd()
-            self.build_iotests = self.source_iotests
+        self.source_iotests = source_dir
+        self.build_iotests = build_dir
 
         self.build_root = os.path.join(self.build_iotests, '..', '..')