diff --git a/src/osmo_gsm_tester/ms_driver.py b/src/osmo_gsm_tester/ms_driver.py
index b29859b..bc1cce9 100644
--- a/src/osmo_gsm_tester/ms_driver.py
+++ b/src/osmo_gsm_tester/ms_driver.py
@@ -93,7 +93,7 @@
         def check_and_return_binary(name):
             """Checks the binary exists and returns the path."""
             binary = inst.child('bin', name)
-            if not os.path.isfile(name):
+            if not os.path.isfile(binary):
                 raise RuntimeError('Binary missing: %r' % binary)
             return binary