diff --git a/bitmap2component/CMakeLists.txt b/bitmap2component/CMakeLists.txt
index 766c303f07..ebf6a5a954 100644
--- a/bitmap2component/CMakeLists.txt
+++ b/bitmap2component/CMakeLists.txt
@@ -10,8 +10,8 @@ include_directories( BEFORE ${INC_BEFORE} )
 include_directories( ${INC_AFTER} )
 
 set( BITMAP2COMPONENT_SRCS
+    ${CMAKE_SOURCE_DIR}/common/base_units.cpp
     ${CMAKE_SOURCE_DIR}/common/single_top.cpp
-
     bitmap2cmp_main.cpp
     bitmap2cmp_settings.cpp
     bitmap2component.cpp
diff --git a/common/base_units.cpp b/common/base_units.cpp
index 3ee7bd2dca..296ff4a70e 100644
--- a/common/base_units.cpp
+++ b/common/base_units.cpp
@@ -41,16 +41,12 @@
 #include <title_block.h>
 
 
-#if defined( PCBNEW ) || defined( CVPCB ) || defined( EESCHEMA ) || defined( GERBVIEW ) || defined( PL_EDITOR )
 #define IU_TO_MM( x )       ( x / IU_PER_MM )
 #define IU_TO_IN( x )       ( x / IU_PER_MILS / 1000 )
 #define IU_TO_MILS( x )     ( x / IU_PER_MILS )
 #define MM_TO_IU( x )       ( x * IU_PER_MM )
 #define IN_TO_IU( x )       ( x * IU_PER_MILS * 1000 )
 #define MILS_TO_IU( x )     ( x * IU_PER_MILS )
-#else
-#error "Cannot resolve internal units due to no definition of EESCHEMA, CVPCB or PCBNEW."
-#endif
 
 
 // Helper function to print a float number without using scientific notation
diff --git a/common/settings/app_settings.cpp b/common/settings/app_settings.cpp
index 320d99827e..5194c2277b 100644
--- a/common/settings/app_settings.cpp
+++ b/common/settings/app_settings.cpp
@@ -25,6 +25,7 @@
 #include <settings/app_settings.h>
 #include <settings/common_settings.h>
 #include <settings/parameters.h>
+#include <base_units.h>
 
 ///! Update the schema version whenever a migration is required
 const int appSettingsSchemaVersion = 0;
@@ -211,7 +212,6 @@ bool APP_SETTINGS_BASE::migrateWindowConfig( wxConfigBase* aCfg, const std::stri
     ret &= fromLegacy<int>(    aCfg,
             aFrame + "_LastGridSize",        aJsonPath + ".grid.last_size" );
 
-#if defined( PCBNEW )
     double x, y;
 
     if( aCfg->Read( aFrame + "PcbUserGrid_X", &x ) && aCfg->Read( aFrame + "PcbUserGrid_Y", &y ) )
@@ -221,7 +221,6 @@ bool APP_SETTINGS_BASE::migrateWindowConfig( wxConfigBase* aCfg, const std::stri
         ( *this )[PointerFromString( ".grid.user_grid_x" )] = StringFromValue( u, x, true, true );
         ( *this )[PointerFromString( ".grid.user_grid_y" )] = StringFromValue( u, y, true, true );
     }
-#endif
 
     ret &= fromLegacy<bool>(   aCfg,
             aFrame + gd + "GridAxesEnabled", aJsonPath + ".grid.axes_enabled" );
diff --git a/include/convert_to_biu.h b/include/convert_to_biu.h
index c54deb5fff..882a5a157d 100644
--- a/include/convert_to_biu.h
+++ b/include/convert_to_biu.h
@@ -86,12 +86,13 @@ constexpr inline int Iu2Mils( int iu )
     return static_cast< int >( mils < 0 ? mils - 0.5 : mils + 0.5 );
 }
 #else
-// Here, we do not know the value of internal units: do not define
-// conversion functions (They do not have meaning)
-#define UNKNOWN_IU
+// Here, we do not know the value of internal units: just use something safe to allow
+// easier packaging of compilation units
+constexpr double IU_PER_MM = 1;
+constexpr double IU_PER_MILS = IU_PER_MM * 0.0254;
 #endif
 
-#ifndef UNKNOWN_IU
+
 // Other definitions used in a few files
 constexpr double MM_PER_IU = ( 1 / IU_PER_MM );
 
@@ -121,6 +122,4 @@ constexpr inline double Iu2Millimeter( int iu )
 constexpr int ARC_LOW_DEF  = Millimeter2iu( 0.02 );
 constexpr int ARC_HIGH_DEF = Millimeter2iu( 0.005 );
 
-#endif
-
 #endif  // CONVERT_TO_BIU_H_
diff --git a/kicad/CMakeLists.txt b/kicad/CMakeLists.txt
index dccd99739f..3c7c43649a 100644
--- a/kicad/CMakeLists.txt
+++ b/kicad/CMakeLists.txt
@@ -15,6 +15,7 @@ include_directories(
 
 
 set( KICAD_SRCS
+    ${CMAKE_SOURCE_DIR}/common/base_units.cpp
     dialogs/dialog_template_selector_base.cpp
     dialogs/dialog_template_selector.cpp
     files-io.cpp
diff --git a/pcb_calculator/CMakeLists.txt b/pcb_calculator/CMakeLists.txt
index 5fa93b0d2d..8ef7ecbc86 100644
--- a/pcb_calculator/CMakeLists.txt
+++ b/pcb_calculator/CMakeLists.txt
@@ -10,6 +10,7 @@ include_directories(
     )
 
 set( PCB_CALCULATOR_SRCS
+    ${CMAKE_SOURCE_DIR}/common/base_units.cpp
     attenuators.cpp
     board_classes_values.cpp
     colorcode.cpp