diff --git a/qucs/components/libcomp.cpp b/qucs/components/libcomp.cpp
index 7bb372b6..96ec0425 100644
--- a/qucs/components/libcomp.cpp
+++ b/qucs/components/libcomp.cpp
@@ -18,6 +18,7 @@
 #include "libcomp.h"
 #include "main.h"
 #include "misc.h"
+#include "node.h"
 #include "extsimkernels/qucs2spice.h"
 #include "extsimkernels/spicecompat.h"
 
diff --git a/qucs/components/mutual2.cpp b/qucs/components/mutual2.cpp
index acff60bc..83f4390d 100644
--- a/qucs/components/mutual2.cpp
+++ b/qucs/components/mutual2.cpp
@@ -16,6 +16,7 @@
  ***************************************************************************/
 
 #include "main.h"
+#include "node.h"
 #include "mutual2.h"
 
 #include<QFontMetrics>
diff --git a/qucs/components/rfedd.cpp b/qucs/components/rfedd.cpp
index 6d836143..5e686f4d 100644
--- a/qucs/components/rfedd.cpp
+++ b/qucs/components/rfedd.cpp
@@ -16,6 +16,7 @@
  ***************************************************************************/
 #include "rfedd.h"
 #include "main.h"
+#include "node.h"
 
 #include <QFileInfo>
 #include <QFontMetrics>
diff --git a/qucs/components/rfedd2p.cpp b/qucs/components/rfedd2p.cpp
index ac9b047d..ecd72367 100644
--- a/qucs/components/rfedd2p.cpp
+++ b/qucs/components/rfedd2p.cpp
@@ -16,6 +16,7 @@
  ***************************************************************************/
 #include "rfedd2p.h"
 #include "main.h"
+#include "node.h"
 
 #include <QFileInfo>
 #include <QFontMetrics>
diff --git a/qucs/components/rlcg.cpp b/qucs/components/rlcg.cpp
index ed1ca5c1..e7186ced 100644
--- a/qucs/components/rlcg.cpp
+++ b/qucs/components/rlcg.cpp
@@ -16,6 +16,7 @@
  ***************************************************************************/
 #include "main.h"
 #include "rlcg.h"
+#include "node.h"
 
 #include "extsimkernels/spicecompat.h"
 
diff --git a/qucs/components/sparamfile.cpp b/qucs/components/sparamfile.cpp
index 09aa3dab..3fca3aa4 100644
--- a/qucs/components/sparamfile.cpp
+++ b/qucs/components/sparamfile.cpp
@@ -17,6 +17,7 @@
 #include "sparamfile.h"
 #include "main.h"
 #include "misc.h"
+#include "node.h"
 
 #include <QFileInfo>
 
diff --git a/qucs/components/spicefile.cpp b/qucs/components/spicefile.cpp
index 86c4fdb5..19d24bf2 100644
--- a/qucs/components/spicefile.cpp
+++ b/qucs/components/spicefile.cpp
@@ -33,6 +33,7 @@
 
 #include "spicefile.h"
 #include "main.h"
+#include "node.h"
 #include "qucs.h"
 #include "misc.h"
 #include "extsimkernels/spicecompat.h"
diff --git a/qucs/components/verilogfile.cpp b/qucs/components/verilogfile.cpp
index af456635..ab473500 100644
--- a/qucs/components/verilogfile.cpp
+++ b/qucs/components/verilogfile.cpp
@@ -18,6 +18,7 @@
 #include "verilogfile.h"
 #include "main.h"
 #include "misc.h"
+#include "node.h"
 
 #include <QTextStream>
 #include <QRegularExpression>
diff --git a/qucs/components/vhdlfile.cpp b/qucs/components/vhdlfile.cpp
index 84e2ea52..f7628203 100644
--- a/qucs/components/vhdlfile.cpp
+++ b/qucs/components/vhdlfile.cpp
@@ -17,6 +17,7 @@
 #include "vhdlfile.h"
 #include "main.h"
 #include "misc.h"
+#include "node.h"
 
 #include <QTextStream>
 #include <QRegularExpression>
diff --git a/qucs/dialogs/labeldialog.cpp b/qucs/dialogs/labeldialog.cpp
index 79ab8973..20c7b54f 100644
--- a/qucs/dialogs/labeldialog.cpp
+++ b/qucs/dialogs/labeldialog.cpp
@@ -17,6 +17,7 @@
 #include "labeldialog.h"
 #include "../wirelabel.h"
 #include "main.h"
+#include "extsimkernels/spicecompat.h"
 
 #include <QLabel>
 #include <QLineEdit>
diff --git a/qucs/main.h b/qucs/main.h
index 3249f8fe..feefe807 100644
--- a/qucs/main.h
+++ b/qucs/main.h
@@ -27,10 +27,6 @@
 #include <QStringList>
 #include <QDir>
 
-#include "wire.h"
-#include "node.h"
-#include "diagrams/diagram.h"
-#include "extsimkernels/spicecompat.h"
 
 class QucsApp;
 class Component;
diff --git a/qucs/module.h b/qucs/module.h
index ea8ca4c5..b49a1c4b 100644
--- a/qucs/module.h
+++ b/qucs/module.h
@@ -21,6 +21,7 @@
 #include <QList>
 #include <QHash>
 #include <QMap>
+#include "component.h"
 
 class QPixmap;
 
diff --git a/qucs/qucs_init.cpp b/qucs/qucs_init.cpp
index 187c0b2c..36f315c4 100644
--- a/qucs/qucs_init.cpp
+++ b/qucs/qucs_init.cpp
@@ -22,6 +22,7 @@
 #include "main.h"
 #include "misc.h"
 #include "qucs.h"
+#include "extsimkernels/spicecompat.h"
 #include "octave_window.h"
 
 #include <QAction>
diff --git a/qucs/spicecomponents/sp_disto.cpp b/qucs/spicecomponents/sp_disto.cpp
index 5e7fd2ab..929aaa50 100644
--- a/qucs/spicecomponents/sp_disto.cpp
+++ b/qucs/spicecomponents/sp_disto.cpp
@@ -18,7 +18,7 @@
 #include "main.h"
 #include "misc.h"
 #include "extsimkernels/spicecompat.h"
-
+#include <cmath>
 
 SpiceDisto::SpiceDisto()
 {
@@ -93,8 +93,8 @@ QString SpiceDisto::spice_netlist(bool isXyce)
             Fstart *= fac;
             misc::str2num(Props.at(2)->Value,Fstop,unit,fac);
             Fstop *= fac;
-            double Nd = ceil(log10(Fstop/Fstart)); // number of decades
-            double Npd = ceil((Np - 1)/Nd); // points per decade
+            double Nd = std::ceil(std::log10(Fstop/Fstart)); // number of decades
+            double Npd = std::ceil((Np - 1)/Nd); // points per decade
             points = QString::number(Npd);
         } else {
             points = Props.at(3)->Value;
diff --git a/qucs/spicecomponents/sp_noise.cpp b/qucs/spicecomponents/sp_noise.cpp
index cbc88a35..d58ac402 100644
--- a/qucs/spicecomponents/sp_noise.cpp
+++ b/qucs/spicecomponents/sp_noise.cpp
@@ -18,6 +18,7 @@
 #include "main.h"
 #include "misc.h"
 #include "extsimkernels/spicecompat.h"
+#include <cmath>
 
 
 SpiceNoise::SpiceNoise()
@@ -94,8 +95,8 @@ QString SpiceNoise::spice_netlist(bool isXyce)
         Fstart *= fac;
         misc::str2num(Props.at(2)->Value,Fstop,unit,fac);
         Fstop *= fac;
-        double Nd = ceil(log10(Fstop/Fstart)); // number of decades
-        double Npd = ceil((Np - 1)/Nd); // points per decade
+        double Nd = std::ceil(std::log10(Fstop/Fstart)); // number of decades
+        double Npd = std::ceil((Np - 1)/Nd); // points per decade
         points = QString::number(Npd);
     } else {
         points = Props.at(3)->Value;
diff --git a/qucs/spicecomponents/spicegeneric.cpp b/qucs/spicecomponents/spicegeneric.cpp
index 890028c2..d88d38ae 100644
--- a/qucs/spicecomponents/spicegeneric.cpp
+++ b/qucs/spicecomponents/spicegeneric.cpp
@@ -20,6 +20,7 @@
 #include "spicegeneric.h"
 
 #include "main.h"
+#include "node.h"
 #include "extsimkernels/spicecompat.h"
 
 
diff --git a/qucs/spicecomponents/spicelibcomp.cpp b/qucs/spicecomponents/spicelibcomp.cpp
index cfd8cc3f..ce3e6493 100644
--- a/qucs/spicecomponents/spicelibcomp.cpp
+++ b/qucs/spicecomponents/spicelibcomp.cpp
@@ -18,6 +18,7 @@
 #include "spicelibcomp.h"
 #include "main.h"
 #include "misc.h"
+#include "node.h"
 #include "extsimkernels/spicecompat.h"
 
 #include <QTextStream>
diff --git a/qucs/spicecomponents/xspicegeneric.cpp b/qucs/spicecomponents/xspicegeneric.cpp
index d8e4e78d..10b85540 100644
--- a/qucs/spicecomponents/xspicegeneric.cpp
+++ b/qucs/spicecomponents/xspicegeneric.cpp
@@ -22,6 +22,7 @@
 #include "xspicegeneric.h"
 
 #include "main.h"
+#include "node.h"
 #include "extsimkernels/spicecompat.h"
 
 
diff --git a/qucs/textdoc.cpp b/qucs/textdoc.cpp
index edcf5ece..554f2097 100644
--- a/qucs/textdoc.cpp
+++ b/qucs/textdoc.cpp
@@ -20,6 +20,7 @@ Copyright (C) 2014 by Guilherme Brondani Torri <guitorri@gmail.com>
 #endif
 #include <QAction>
 #include <QMessageBox>
+#include <QTextStream>
 
 #include "main.h"
 #include "misc.h"