diff --git a/cmake/test-protobuf.cpp b/cmake/test-protobuf.cpp
index eab6dd90d..8d7796473 100644
--- a/cmake/test-protobuf.cpp
+++ b/cmake/test-protobuf.cpp
@@ -38,6 +38,8 @@ int main(int argc, char *argv[]) {
 
   Success sc;
   sc.set_message("test");
-  sc.SerializeToOstream(&std::cerr);
+  if (!sc.SerializeToOstream(&std::cerr)) {
+      return -1;
+  }
   return 0;
 }
diff --git a/src/device_trezor/trezor/messages_map.cpp b/src/device_trezor/trezor/messages_map.cpp
index 79fd87668..2f275e7ba 100644
--- a/src/device_trezor/trezor/messages_map.cpp
+++ b/src/device_trezor/trezor/messages_map.cpp
@@ -71,9 +71,9 @@ namespace trezor
 
   google::protobuf::Message * MessageMapper::get_message(const std::string & msg_name) {
     // Each package instantiation so lookup works
-    hw::trezor::messages::common::Success::default_instance();
-    hw::trezor::messages::management::Cancel::default_instance();
-    hw::trezor::messages::monero::MoneroGetAddress::default_instance();
+    (void)hw::trezor::messages::common::Success::default_instance();
+    (void)hw::trezor::messages::management::Cancel::default_instance();
+    (void)hw::trezor::messages::monero::MoneroGetAddress::default_instance();
 
 #ifdef WITH_TREZOR_DEBUGGING
     hw::trezor::messages::debug::DebugLinkDecision::default_instance();