diff --git a/wscript b/wscript
index 219e70e3d..f47c67b67 100644
--- a/wscript
+++ b/wscript
@@ -518,7 +518,7 @@ def check(bld):
 
     if env['ENABLE_PYTHON_BINDINGS']:
         print "-- Running NS-3 Python bindings unit tests..."
-        wutils.run_argv([env['PYTHON'], env, os.path.join("utils", "python-unit-tests.py")], proc_env)
+        wutils.run_argv([env['PYTHON'], os.path.join("utils", "python-unit-tests.py")], env, proc_env)
     else:
         print "-- Skipping NS-3 Python bindings unit tests: Python bindings not enabled."