diff --git a/google_keymaster_test.cpp b/google_keymaster_test.cpp
index 18befde..2748656 100644
--- a/google_keymaster_test.cpp
+++ b/google_keymaster_test.cpp
@@ -36,6 +36,7 @@
     int result = RUN_ALL_TESTS();
     // Clean up stuff OpenSSL leaves around, so Valgrind doesn't complain.
     CRYPTO_cleanup_all_ex_data();
+    ERR_remove_thread_state(NULL);
     ERR_free_strings();
     return result;
 }