diff --git a/mesonbuild/mtest.py b/mesonbuild/mtest.py
index 31349eabd..b5b131667 100644
--- a/mesonbuild/mtest.py
+++ b/mesonbuild/mtest.py
@@ -1681,6 +1681,8 @@ class TestHarness:
             sys.exit(125)
 
         self.name_max_len = max(uniwidth(self.get_pretty_suite(test)) for test in tests)
+        self.options.num_processes = min(self.options.num_processes,
+                                         len(tests) * self.options.repeat)
         startdir = os.getcwd()
         try:
             os.chdir(self.options.wd)