diff --git a/dumux/freeflow/zeroeq/zeroeqmodel.hh b/dumux/freeflow/zeroeq/zeroeqmodel.hh
index b629c57d5d07d4d4d81c7c71a3e7ffc934639871..426c5535a4ce63893c521be85913c8fb49ab3e9d 100644
--- a/dumux/freeflow/zeroeq/zeroeqmodel.hh
+++ b/dumux/freeflow/zeroeq/zeroeqmodel.hh
@@ -280,6 +280,7 @@ public:
      * \brief Writes the data into the volVarsData.csv file
      *
      * \param stream The output file stream
+     * \param volVars The volume variables
      */
     void writeVolVarsData(std::ofstream &stream, const VolumeVariables &volVars)
     {
@@ -314,6 +315,7 @@ public:
      * \brief Writes the data into the fluxVarsData.csv file
      *
      * \param stream The output file stream
+     * \param fluxVars The flux variables
      */
     void writeFluxVarsData(std::ofstream &stream, const FluxVariables &fluxVars)
     {