diff --git a/source3/utils/ntlm_auth_diagnostics.c b/source3/utils/ntlm_auth_diagnostics.c
index 5ea8f821c45..69034434148 100644
--- a/source3/utils/ntlm_auth_diagnostics.c
+++ b/source3/utils/ntlm_auth_diagnostics.c
@@ -438,6 +438,8 @@ static bool test_lmv2_ntlmv2_broken(enum ntlm_break break_which)
 		dump_data(1, ntlmv2_session_key.data, ntlmv2_session_key.length);
 		pass = False;
 	}
+
+	data_blob_free(&ntlmv2_session_key);
         return pass;
 }