diff --git a/tests/run-tests.py b/tests/run-tests.py
index f57f891eb88e0988e90a3824cfab2116b55e9248_dGVzdHMvcnVuLXRlc3RzLnB5..4bc35496136fa8b634c51bc9479ed5282bdfb3c7_dGVzdHMvcnVuLXRlc3RzLnB5 100755
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -598,6 +598,8 @@
     f.close()
 
     script = []
+    if options.debug:
+        script.append('set -x\n')
     if os.getenv('MSYSTEM'):
         script.append('alias pwd="pwd -W"\n')
     for n, l in enumerate(t):