diff --git a/eeschema/sim/ngspice.cpp b/eeschema/sim/ngspice.cpp
index 778cce75e7..39a75d3068 100644
--- a/eeschema/sim/ngspice.cpp
+++ b/eeschema/sim/ngspice.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2016-2018 CERN
+ * Copyright (C) 2016-2022 CERN
  * Copyright (C) 2018-2022 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
@@ -277,9 +277,9 @@ bool NGSPICE::Attach( const std::shared_ptr<SIMULATION_MODEL>& aModel, REPORTER&
 
 bool NGSPICE::LoadNetlist( const string& aNetlist )
 {
-    LOCALE_IO c_locale;       // ngspice works correctly only with C locale
+    LOCALE_IO     c_locale;       // ngspice works correctly only with C locale
     vector<char*> lines;
-    stringstream ss( aNetlist );
+    stringstream  ss( aNetlist );
 
     m_netlist = "";
 
@@ -296,7 +296,7 @@ bool NGSPICE::LoadNetlist( const string& aNetlist )
     Command( "remcirc" );
     bool success = !m_ngSpice_Circ( lines.data() );
 
-    for( auto line : lines )
+    for( char* line : lines )
         free( line );
 
     return success;
diff --git a/eeschema/sim/ngspice.h b/eeschema/sim/ngspice.h
index 78b17ec7cb..1b8bd2b85e 100644
--- a/eeschema/sim/ngspice.h
+++ b/eeschema/sim/ngspice.h
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2016 CERN
+ * Copyright (C) 2016-2022 CERN
  * Copyright (C) 2021-2022 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
@@ -155,14 +155,12 @@ private:
     // Assure ngspice is in a valid state and reinitializes it if need be.
     void validate();
 
-    ///< Error flag indicating that ngspice needs to be reloaded.
-    bool m_error;
+private:
+    bool        m_error;            ///< Error flag indicating that ngspice needs to be reloaded.
 
-    ///< Ngspice should be initialized only once.
-    static bool m_initialized;
+    static bool m_initialized;      ///< Ngspice should be initialized only once.
 
-    ///< Current netlist
-    std::string m_netlist;
+    std::string m_netlist;          ///< Current netlist
 };
 
 #endif /* NGSPICE_H */