diff --git a/gene_marker.cpp b/gene_marker.cpp
index ee03857..964be65 100644
--- a/gene_marker.cpp
+++ b/gene_marker.cpp
@@ -15,7 +15,7 @@
 bool checkArguments(int argc, char* argv[]) {
 	if (argc != 3) {
 		std::cerr << "Usage: " << argv[0]
-			  << " input_file output_file\n";
+			  << " <input_file> <output_file>\n";
 		return false;
 	}
 	return true;