--- a/reduze/files.cpp
+++ b/reduze/files.cpp
@@ -723,7 +723,7 @@
 	string file_name_tmp = file_name + ".tmp";
 	ofstream file(file_name_tmp.c_str());
 	if (!file)
-		ABORT("Can't write to " << file);
+		ABORT("Can't write to " << file_name_tmp);
 	Emitter os;
 	os << BeginMap;
 	os << Key << "crossings" << Value;
@@ -752,7 +752,7 @@
 	string file_name_tmp = file_name + ".tmp";
 	ofstream file(file_name_tmp.c_str());
 	if (!file)
-		ABORT("Can't write to " << file);
+		ABORT("Can't write to " << file_name_tmp);
 	os << YAML::BeginMap << YAML::Key << "sectormappings" << YAML::Value;
 	os << m << YAML::EndMap;
 	file << os.c_str();
@@ -1036,7 +1036,7 @@
 
 bool is_readable_file(const string& filename) {
 	ifstream is(filename.c_str());
-	bool ok = is;
+	bool ok = !is.fail();
 	is.close();
 	return ok && !is_readable_directory(filename);
 }