diff --git a/cpp/switchchain.cpp b/cpp/switchchain.cpp
index 1871aab3959c58061aacb964393eab7fa2c222a5..6d02203eed4a5c9ae25660a37b4c29a3cbd7f315 100644
--- a/cpp/switchchain.cpp
+++ b/cpp/switchchain.cpp
@@ -258,7 +258,7 @@ int main() {
                           << "%)." << std::endl;
 
                 if (outputComma)
-                    outfile << ',';
+                    outfile << ',' << '\n';
                 outputComma = true;
 
                 std::sort(ds.begin(), ds.end());