diff --git a/pcb_calculator/CMakeLists.txt b/pcb_calculator/CMakeLists.txt
index 8b13f0d76a..756a65805a 100644
--- a/pcb_calculator/CMakeLists.txt
+++ b/pcb_calculator/CMakeLists.txt
@@ -1,9 +1,6 @@
 include_directories( BEFORE ${INC_BEFORE} )
 include_directories(
-    bitmaps
     dialogs
-    transline
-    attenuators
     ${CMAKE_SOURCE_DIR}/common
     ${INC_AFTER}
     )
diff --git a/pcb_calculator/attenuators/attenuator_classes.cpp b/pcb_calculator/attenuators/attenuator_classes.cpp
index ff026d0326..79cd018307 100644
--- a/pcb_calculator/attenuators/attenuator_classes.cpp
+++ b/pcb_calculator/attenuators/attenuator_classes.cpp
@@ -5,7 +5,7 @@
 **     since 2006/6/14
 **
 *****************************************************************************/
-#include <cmath>
+#include <wx/bitmap.h>
 
 #include <i18n_utility.h>
 #include <kiface_i.h>
@@ -14,27 +14,27 @@
 #include "pcb_calculator_settings.h"
 
 // Bitmaps:
-#include <att_bridge.xpm>
-#include <att_pi.xpm>
-#include <att_splitter.xpm>
-#include <att_tee.xpm>
+#include "bitmaps/att_bridge.xpm"
+#include "bitmaps/att_pi.xpm"
+#include "bitmaps/att_splitter.xpm"
+#include "bitmaps/att_tee.xpm"
 
 
 // Html texts showing the formulas
 wxString pi_formula =
-#include <pi_formula.h>
+#include "attenuators/pi_formula.h"
 
 
 wxString tee_formula =
-#include <tee_formula.h>
+#include "attenuators/tee_formula.h"
 
 
 wxString bridget_tee_formula =
-#include <bridget_tee_formula.h>
+#include "attenuators/bridget_tee_formula.h"
 
 
 wxString splitter_formula =
-#include <splitter_formula.h>
+#include "attenuators/splitter_formula.h"
 
 
 
diff --git a/pcb_calculator/attenuators/attenuator_classes.h b/pcb_calculator/attenuators/attenuator_classes.h
index f8078dcd89..1c459651fe 100644
--- a/pcb_calculator/attenuators/attenuator_classes.h
+++ b/pcb_calculator/attenuators/attenuator_classes.h
@@ -12,7 +12,8 @@
 #ifndef ATTENUATORFUNC_H
 #define ATTENUATORFUNC_H
 
-#include <wx/bitmap.h>
+class wxBitmap;
+class wxString;
 
 enum ATTENUATORS_TYPE {
     PI_TYPE,
diff --git a/pcb_calculator/params_read_write.cpp b/pcb_calculator/params_read_write.cpp
index acd509c2d1..3a462c4c39 100644
--- a/pcb_calculator/params_read_write.cpp
+++ b/pcb_calculator/params_read_write.cpp
@@ -20,11 +20,10 @@
 
 #include <wx/app.h>
 #include <wx/colour.h>
-#include <wx/log.h>
 #include <wx/msgdlg.h>
 
 #include "pcb_calculator_frame.h"
-#include "transline.h"
+#include "transline/transline.h"
 
 /*
  * Return the value from a string,
diff --git a/pcb_calculator/pcb_calculator_frame.h b/pcb_calculator/pcb_calculator_frame.h
index a079001087..bc79ed3ed7 100644
--- a/pcb_calculator/pcb_calculator_frame.h
+++ b/pcb_calculator/pcb_calculator_frame.h
@@ -24,7 +24,7 @@
 #ifndef PCB_CALCULATOR_H
 #define PCB_CALCULATOR_H
 
-#include "transline.h" // Included for SUBST_PRMS_ID definition.
+#include "transline/transline.h" // Included for SUBST_PRMS_ID definition.
 #include "transline_ident.h"
 #include "pcb_calculator_frame_base.h"
 
diff --git a/pcb_calculator/transline/c_microstrip.h b/pcb_calculator/transline/c_microstrip.h
index 44eb04791a..85b4b07d4f 100644
--- a/pcb_calculator/transline/c_microstrip.h
+++ b/pcb_calculator/transline/c_microstrip.h
@@ -25,8 +25,8 @@
 #ifndef _C_MICROSTRIP_H_
 #define _C_MICROSTRIP_H_
 
-#include <microstrip.h>
-#include <transline.h>
+#include "transline/microstrip.h"
+#include "transline/transline.h"
 
 class C_MICROSTRIP : public TRANSLINE
 {
diff --git a/pcb_calculator/transline/coax.h b/pcb_calculator/transline/coax.h
index e56c2551c8..56c51338ee 100644
--- a/pcb_calculator/transline/coax.h
+++ b/pcb_calculator/transline/coax.h
@@ -25,7 +25,7 @@
 #ifndef __COAX_H
 #define __COAX_H
 
-#include <transline.h>
+#include "transline/transline.h"
 
 class COAX : public TRANSLINE
 {
diff --git a/pcb_calculator/transline/coplanar.h b/pcb_calculator/transline/coplanar.h
index e7a3c57b8e..7ceaffc7e7 100644
--- a/pcb_calculator/transline/coplanar.h
+++ b/pcb_calculator/transline/coplanar.h
@@ -25,7 +25,7 @@
 #ifndef __COPLANAR_H
 #define __COPLANAR_H
 
-#include <transline.h>
+#include "transline/transline.h"
 
 class COPLANAR : public TRANSLINE
 {
diff --git a/pcb_calculator/transline/microstrip.h b/pcb_calculator/transline/microstrip.h
index 57eb922900..dbaec6573e 100644
--- a/pcb_calculator/transline/microstrip.h
+++ b/pcb_calculator/transline/microstrip.h
@@ -25,7 +25,7 @@
 #ifndef __MICROSTRIP_H
 #define __MICROSTRIP_H
 
-#include <transline.h>
+#include "transline/transline.h"
 
 class MICROSTRIP : public TRANSLINE
 {
diff --git a/pcb_calculator/transline/rectwaveguide.h b/pcb_calculator/transline/rectwaveguide.h
index 6a38d3ff77..68ae5d2f90 100644
--- a/pcb_calculator/transline/rectwaveguide.h
+++ b/pcb_calculator/transline/rectwaveguide.h
@@ -25,7 +25,7 @@
 #ifndef __RECTWAVEGUIDE_H
 #define __RECTWAVEGUIDE_H
 
-#include <transline.h>
+#include "transline/transline.h"
 
 #define PHYS_A_PRM PHYS_WIDTH_PRM
 #define PHYS_B_PRM PHYS_S_PRM
diff --git a/pcb_calculator/transline/stripline.h b/pcb_calculator/transline/stripline.h
index c033776565..1315c26ecd 100644
--- a/pcb_calculator/transline/stripline.h
+++ b/pcb_calculator/transline/stripline.h
@@ -25,7 +25,7 @@
 #define __STRIPLINE_H
 
 
-#include <transline.h>
+#include "transline/transline.h"
 
 class STRIPLINE : public TRANSLINE
 {
diff --git a/pcb_calculator/transline/twistedpair.h b/pcb_calculator/transline/twistedpair.h
index 74e8eec844..26fb3dcfc6 100644
--- a/pcb_calculator/transline/twistedpair.h
+++ b/pcb_calculator/transline/twistedpair.h
@@ -24,7 +24,7 @@
 #ifndef __TWISTEDPAIR_H
 #define __TWISTEDPAIR_H
 
-#include <transline.h>
+#include "transline/transline.h"
 
 class TWISTEDPAIR : public TRANSLINE
 {
diff --git a/pcb_calculator/transline_dlg_funct.cpp b/pcb_calculator/transline_dlg_funct.cpp
index 3c0b0f2f01..a90fe41b34 100644
--- a/pcb_calculator/transline_dlg_funct.cpp
+++ b/pcb_calculator/transline_dlg_funct.cpp
@@ -24,7 +24,6 @@
 
 #include "common_data.h"
 #include "pcb_calculator_frame.h"
-#include "widgets/unit_selector.h"
 
 extern double DoubleFromString( const wxString& TextValue );
 
diff --git a/pcb_calculator/transline_ident.cpp b/pcb_calculator/transline_ident.cpp
index 0b1fe34207..8415d86e00 100644
--- a/pcb_calculator/transline_ident.cpp
+++ b/pcb_calculator/transline_ident.cpp
@@ -24,28 +24,28 @@
 #include <wx/intl.h>
 #include <wx/arrstr.h>
 
+#include <kiface_i.h>
 
 // Bitmaps:
-#include <c_microstrip.xpm>
-#include <microstrip.xpm>
-#include <twistedpair.xpm>
-#include <coax.xpm>
-#include <cpw.xpm>
-#include <cpw_back.xpm>
-#include <stripline.xpm>
-#include <rectwaveguide.xpm>
+#include "bitmaps/c_microstrip.xpm"
+#include "bitmaps/microstrip.xpm"
+#include "bitmaps/twistedpair.xpm"
+#include "bitmaps/coax.xpm"
+#include "bitmaps/cpw.xpm"
+#include "bitmaps/cpw_back.xpm"
+#include "bitmaps/stripline.xpm"
+#include "bitmaps/rectwaveguide.xpm"
 
 // transline specific functions:
-#include <transline.h>
-#include <microstrip.h>
-#include <coplanar.h>
-#include <rectwaveguide.h>
-#include <coax.h>
-#include <c_microstrip.h>
-#include <stripline.h>
-#include <twistedpair.h>
+#include "transline/transline.h"
+#include "transline/microstrip.h"
+#include "transline/coplanar.h"
+#include "transline/rectwaveguide.h"
+#include "transline/coax.h"
+#include "transline/c_microstrip.h"
+#include "transline/stripline.h"
+#include "transline/twistedpair.h"
 
-#include <kiface_i.h>
 #include "pcb_calculator_settings.h"
 #include "widgets/unit_selector.h"
 #include "transline_ident.h"
diff --git a/pcb_calculator/transline_ident.h b/pcb_calculator/transline_ident.h
index 7d1695d7de..d0d93da62d 100644
--- a/pcb_calculator/transline_ident.h
+++ b/pcb_calculator/transline_ident.h
@@ -28,7 +28,7 @@
 #include <vector>
 #include <wx/bitmap.h>
 
-#include "transline.h"
+#include "transline/transline.h"
 
 // An enum to handle muwave shapes:
 enum TRANSLINE_TYPE_ID {
diff --git a/pcb_calculator/widgets/unit_selector.h b/pcb_calculator/widgets/unit_selector.h
index e6ede59c60..c0788af246 100644
--- a/pcb_calculator/widgets/unit_selector.h
+++ b/pcb_calculator/widgets/unit_selector.h
@@ -23,8 +23,8 @@
   * a wxChoiceBox to select units in Pcb_Calculator
   */
 
-#ifndef _UnitSelector_h_
-#define _UnitSelector_h_
+#ifndef UNIT_SELECTOR_H
+#define UNIT_SELECTOR_H
 
 
 #include <wx/string.h>
@@ -129,5 +129,5 @@ public:
     virtual double GetUnitScale() override;
 };
 
-#endif  // _UnitSelector_h_
+#endif  // UNIT_SELECTOR_H