diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index 52dab5dd42..9ec4d806e1 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -1369,8 +1369,11 @@ testConnectAuthenticate(virConnectPtr conn,
     ssize_t i;
     char *username = NULL, *password = NULL;
 
-    if (privconn->numAuths == 0)
+    testDriverLock(privconn);
+    if (privconn->numAuths == 0) {
+        testDriverUnlock(privconn);
         return 0;
+    }
 
     /* Authentication is required because the test XML contains a
      * non-empty <auth/> section.  First we must ask for a username.
@@ -1410,6 +1413,7 @@ testConnectAuthenticate(virConnectPtr conn,
 
     ret = 0;
  cleanup:
+    testDriverUnlock(privconn);
     VIR_FREE(username);
     VIR_FREE(password);
     return ret;