diff --git a/core/android.cpp b/core/android.cpp
index 103f18866..9ea1ec971 100644
--- a/core/android.cpp
+++ b/core/android.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* implements Android specific functions */
 #include "dive.h"
 #include "display.h"
diff --git a/core/checkcloudconnection.cpp b/core/checkcloudconnection.cpp
index a0117d4f6..2147d90e4 100644
--- a/core/checkcloudconnection.cpp
+++ b/core/checkcloudconnection.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <QObject>
 #include <QTimer>
 #include <QNetworkAccessManager>
diff --git a/core/checkcloudconnection.h b/core/checkcloudconnection.h
index 58a412797..8d1bc241b 100644
--- a/core/checkcloudconnection.h
+++ b/core/checkcloudconnection.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef CHECKCLOUDCONNECTION_H
 #define CHECKCLOUDCONNECTION_H
 
diff --git a/core/cloudstorage.cpp b/core/cloudstorage.cpp
index 6cbc76991..b6a16f8d2 100644
--- a/core/cloudstorage.cpp
+++ b/core/cloudstorage.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "cloudstorage.h"
 #include "pref.h"
 #include "dive.h"
diff --git a/core/cloudstorage.h b/core/cloudstorage.h
index 6addb739d..13de04283 100644
--- a/core/cloudstorage.h
+++ b/core/cloudstorage.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef CLOUD_STORAGE_H
 #define CLOUD_STORAGE_H
 
@@ -24,4 +25,4 @@ private:
 };
 
 QNetworkAccessManager *manager();
-#endif
\ No newline at end of file
+#endif
diff --git a/core/color.cpp b/core/color.cpp
index cf6f43916..e63f6e569 100644
--- a/core/color.cpp
+++ b/core/color.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "color.h"
 
 QMap<color_indice_t, QVector<QColor> > profile_color;
diff --git a/core/color.h b/core/color.h
index 57ad77242..bd0dbad3a 100644
--- a/core/color.h
+++ b/core/color.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef COLOR_H
 #define COLOR_H
 
diff --git a/core/configuredivecomputer.cpp b/core/configuredivecomputer.cpp
index db2ca196f..730cec25b 100644
--- a/core/configuredivecomputer.cpp
+++ b/core/configuredivecomputer.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "configuredivecomputer.h"
 #include <QTextStream>
 #include <QFile>
diff --git a/core/configuredivecomputer.h b/core/configuredivecomputer.h
index f14eeeca3..c70e9cfa4 100644
--- a/core/configuredivecomputer.h
+++ b/core/configuredivecomputer.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef CONFIGUREDIVECOMPUTER_H
 #define CONFIGUREDIVECOMPUTER_H
 
diff --git a/core/configuredivecomputerthreads.cpp b/core/configuredivecomputerthreads.cpp
index 3f7c4f610..1c445f02a 100644
--- a/core/configuredivecomputerthreads.cpp
+++ b/core/configuredivecomputerthreads.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "configuredivecomputerthreads.h"
 #include "libdivecomputer/hw_ostc.h"
 #include "libdivecomputer/hw_ostc3.h"
diff --git a/core/configuredivecomputerthreads.h b/core/configuredivecomputerthreads.h
index 8817d848a..50ad8c0ce 100644
--- a/core/configuredivecomputerthreads.h
+++ b/core/configuredivecomputerthreads.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef CONFIGUREDIVECOMPUTERTHREADS_H
 #define CONFIGUREDIVECOMPUTERTHREADS_H
 
diff --git a/core/devicedetails.cpp b/core/devicedetails.cpp
index a917a4d0e..e21983a79 100644
--- a/core/devicedetails.cpp
+++ b/core/devicedetails.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "devicedetails.h"
 
 gas::gas(unsigned char oxygen, unsigned char helium, unsigned char type, unsigned char depth) :
diff --git a/core/devicedetails.h b/core/devicedetails.h
index ff3009bc5..ac12b6ca4 100644
--- a/core/devicedetails.h
+++ b/core/devicedetails.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DEVICEDETAILS_H
 #define DEVICEDETAILS_H
 
diff --git a/core/display.h b/core/display.h
index adda5c03a..6d74b5c87 100644
--- a/core/display.h
+++ b/core/display.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DISPLAY_H
 #define DISPLAY_H
 
diff --git a/core/dive.c b/core/dive.c
index 7e9390682..b4a015c1f 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* dive.c */
 /* maintains the internal dive list structure */
 #include <string.h>
diff --git a/core/dive.h b/core/dive.h
index bc029dbcd..fa6133bd3 100644
--- a/core/dive.h
+++ b/core/dive.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DIVE_H
 #define DIVE_H
 
diff --git a/core/divecomputer.cpp b/core/divecomputer.cpp
index 6519e4fba..820a20a51 100644
--- a/core/divecomputer.cpp
+++ b/core/divecomputer.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "divecomputer.h"
 #include "dive.h"
 #include "subsurface-qt/SettingsObjectWrapper.h"
diff --git a/core/divecomputer.h b/core/divecomputer.h
index 98d12ab8b..d58b22b68 100644
--- a/core/divecomputer.h
+++ b/core/divecomputer.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DIVECOMPUTER_H
 #define DIVECOMPUTER_H
 
diff --git a/core/divelogexportlogic.cpp b/core/divelogexportlogic.cpp
index 11c1485b0..e904b85e6 100644
--- a/core/divelogexportlogic.cpp
+++ b/core/divelogexportlogic.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <QString>
 #include <QFile>
 #include <QFileInfo>
diff --git a/core/divelogexportlogic.h b/core/divelogexportlogic.h
index 84f09c362..4279495a0 100644
--- a/core/divelogexportlogic.h
+++ b/core/divelogexportlogic.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DIVELOGEXPORTLOGIC_H
 #define DIVELOGEXPORTLOGIC_H
 
diff --git a/core/divesite.c b/core/divesite.c
index cbcc89d91..b601b4771 100644
--- a/core/divesite.c
+++ b/core/divesite.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* divesite.c */
 #include "divesite.h"
 #include "dive.h"
diff --git a/core/divesite.cpp b/core/divesite.cpp
index ae102a14b..20e33dda1 100644
--- a/core/divesite.cpp
+++ b/core/divesite.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "divesite.h"
 #include "pref.h"
 
diff --git a/core/divesite.h b/core/divesite.h
index 0c38f3556..24f6a0f3f 100644
--- a/core/divesite.h
+++ b/core/divesite.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DIVESITE_H
 #define DIVESITE_H
 
diff --git a/core/divesitehelpers.cpp b/core/divesitehelpers.cpp
index 3542f96fa..a680eef34 100644
--- a/core/divesitehelpers.cpp
+++ b/core/divesitehelpers.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 //
 // infrastructure to deal with dive sites
 //
diff --git a/core/divesitehelpers.h b/core/divesitehelpers.h
index a08069bc0..a6a347b69 100644
--- a/core/divesitehelpers.h
+++ b/core/divesitehelpers.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DIVESITEHELPERS_H
 #define DIVESITEHELPERS_H
 
diff --git a/core/equipment.c b/core/equipment.c
index 5dbb68e3f..3eccfd6b5 100644
--- a/core/equipment.c
+++ b/core/equipment.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifdef __clang__
 // Clang has a bug on zero-initialization of C structs.
 #pragma clang diagnostic ignored "-Wmissing-field-initializers"
diff --git a/core/exif.cpp b/core/exif.cpp
index b2423ba20..9d1643a0a 100644
--- a/core/exif.cpp
+++ b/core/exif.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-2-CLAUSE
 /**************************************************************************
   exif.cpp  -- A simple ISO C++ library to parse basic EXIF
                information from a JPEG file.
diff --git a/core/exif.h b/core/exif.h
index 7c0ac5385..4b1d8e593 100644
--- a/core/exif.h
+++ b/core/exif.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-2-CLAUSE
 /**************************************************************************
   exif.h  -- A simple ISO C++ library to parse basic EXIF
              information from a JPEG file.
diff --git a/core/gas-model.c b/core/gas-model.c
index 98139337c..dd84e9b9d 100644
--- a/core/gas-model.c
+++ b/core/gas-model.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* gas-model.c */
 /* gas compressibility model */
 #include <stdio.h>
diff --git a/core/gaspressures.c b/core/gaspressures.c
index 146086483..2c9f87668 100644
--- a/core/gaspressures.c
+++ b/core/gaspressures.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*  gaspressures.c
  *  ---------------
  *  This file contains the routines to calculate the gas pressures in the cylinders.
diff --git a/core/gaspressures.h b/core/gaspressures.h
index 420c117a2..7e4330e69 100644
--- a/core/gaspressures.h
+++ b/core/gaspressures.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef GASPRESSURES_H
 #define GASPRESSURES_H
 
diff --git a/core/gettext.h b/core/gettext.h
index 43ff023c7..ed2f56d78 100644
--- a/core/gettext.h
+++ b/core/gettext.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef MYGETTEXT_H
 #define MYGETTEXT_H
 
diff --git a/core/gettextfromc.cpp b/core/gettextfromc.cpp
index 43ee8da50..8d1bbc1bd 100644
--- a/core/gettextfromc.cpp
+++ b/core/gettextfromc.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <QCoreApplication>
 #include <QString>
 #include "gettextfromc.h"
diff --git a/core/gettextfromc.h b/core/gettextfromc.h
index 53df18365..5f22d8647 100644
--- a/core/gettextfromc.h
+++ b/core/gettextfromc.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef GETTEXTFROMC_H
 #define GETTEXTFROMC_H
 
diff --git a/core/gpslocation.cpp b/core/gpslocation.cpp
index ead072772..1c5d378cf 100644
--- a/core/gpslocation.cpp
+++ b/core/gpslocation.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "core/gpslocation.h"
 #include "qt-models/gpslistmodel.h"
 #include "core/pref.h"
diff --git a/core/gpslocation.h b/core/gpslocation.h
index 0e333ed82..34e0708ff 100644
--- a/core/gpslocation.h
+++ b/core/gpslocation.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef GPSLOCATION_H
 #define GPSLOCATION_H
 
diff --git a/core/helpers.h b/core/helpers.h
index 7acbeaff6..d694be941 100644
--- a/core/helpers.h
+++ b/core/helpers.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * helpers.h
  *
diff --git a/core/imagedownloader.cpp b/core/imagedownloader.cpp
index 16c48a00e..e405215f8 100644
--- a/core/imagedownloader.cpp
+++ b/core/imagedownloader.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "dive.h"
 #include "metrics.h"
 #include "divelist.h"
diff --git a/core/imagedownloader.h b/core/imagedownloader.h
index f4e3df875..51ccc5f7a 100644
--- a/core/imagedownloader.h
+++ b/core/imagedownloader.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef IMAGEDOWNLOADER_H
 #define IMAGEDOWNLOADER_H
 
diff --git a/core/isocialnetworkintegration.cpp b/core/isocialnetworkintegration.cpp
index eb1e82a49..1786254f3 100644
--- a/core/isocialnetworkintegration.cpp
+++ b/core/isocialnetworkintegration.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "isocialnetworkintegration.h"
 
 //Hack for moc.
diff --git a/core/isocialnetworkintegration.h b/core/isocialnetworkintegration.h
index 70ea3d9ab..74abfeac3 100644
--- a/core/isocialnetworkintegration.h
+++ b/core/isocialnetworkintegration.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef ISOCIALNETWORKINTEGRATION_H
 #define ISOCIALNETWORKINTEGRATION_H
 
@@ -70,4 +71,4 @@ public:
 	virtual void requestUpload() = 0;
 };
 
-#endif
\ No newline at end of file
+#endif
diff --git a/core/load-git.c b/core/load-git.c
index fdac2ef8c..59bb4ef71 100644
--- a/core/load-git.c
+++ b/core/load-git.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifdef __clang__
 // Clang has a bug on zero-initialization of C structs.
 #pragma clang diagnostic ignored "-Wmissing-field-initializers"
diff --git a/core/metrics.cpp b/core/metrics.cpp
index 3c66528b8..23bf14253 100644
--- a/core/metrics.cpp
+++ b/core/metrics.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * metrics.cpp
  *
diff --git a/core/metrics.h b/core/metrics.h
index ca281b3b1..4c636bcc4 100644
--- a/core/metrics.h
+++ b/core/metrics.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * metrics.h
  *
diff --git a/core/ostctools.c b/core/ostctools.c
index 7eaa50a85..413841ad0 100644
--- a/core/ostctools.c
+++ b/core/ostctools.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/core/pluginmanager.cpp b/core/pluginmanager.cpp
index 880ba2a0e..884674ec8 100644
--- a/core/pluginmanager.cpp
+++ b/core/pluginmanager.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "pluginmanager.h"
 
 #include <QApplication>
diff --git a/core/pluginmanager.h b/core/pluginmanager.h
index 3f43b5db1..07ded5902 100644
--- a/core/pluginmanager.h
+++ b/core/pluginmanager.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef PLUGINMANAGER_H
 #define PLUGINMANAGER_H
 
diff --git a/core/profile.c b/core/profile.c
index 0f7bbe0bd..fc2b478e1 100644
--- a/core/profile.c
+++ b/core/profile.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* profile.c */
 /* creates all the necessary data for drawing the dive profile
  */
diff --git a/core/profile.h b/core/profile.h
index 84913036c..0fd284d47 100644
--- a/core/profile.h
+++ b/core/profile.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef PROFILE_H
 #define PROFILE_H
 
diff --git a/core/qt-gui.h b/core/qt-gui.h
index 92532d22f..59e79c268 100644
--- a/core/qt-gui.h
+++ b/core/qt-gui.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef QT_GUI_H
 #define QT_GUI_H
 
diff --git a/core/qt-init.cpp b/core/qt-init.cpp
index fbb755c47..9eebd8421 100644
--- a/core/qt-init.cpp
+++ b/core/qt-init.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <QApplication>
 #include <QNetworkProxy>
 #include <QLibraryInfo>
diff --git a/core/qthelper.cpp b/core/qthelper.cpp
index 126792d52..79fc0effc 100644
--- a/core/qthelper.cpp
+++ b/core/qthelper.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "qthelper.h"
 #include "helpers.h"
 #include "gettextfromc.h"
diff --git a/core/qthelper.h b/core/qthelper.h
index bc1268456..9788bb55d 100644
--- a/core/qthelper.h
+++ b/core/qthelper.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef QTHELPER_H
 #define QTHELPER_H
 
diff --git a/core/qthelperfromc.h b/core/qthelperfromc.h
index c23065a28..4b2ef3d53 100644
--- a/core/qthelperfromc.h
+++ b/core/qthelperfromc.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef QTHELPERFROMC_H
 #define QTHELPERFROMC_H
 
diff --git a/core/qtserialbluetooth.cpp b/core/qtserialbluetooth.cpp
index 2fef1c754..b8c57204e 100644
--- a/core/qtserialbluetooth.cpp
+++ b/core/qtserialbluetooth.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 
 #include <QtBluetooth/QBluetoothAddress>
diff --git a/core/serial_ftdi.c b/core/serial_ftdi.c
index 202895cc0..eafe4f1d7 100644
--- a/core/serial_ftdi.c
+++ b/core/serial_ftdi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: LGPL-2.1+
 /*
  * libdivecomputer
  *
diff --git a/core/subsurface-qt/CylinderObjectHelper.cpp b/core/subsurface-qt/CylinderObjectHelper.cpp
index 341d30b12..ccff48d36 100644
--- a/core/subsurface-qt/CylinderObjectHelper.cpp
+++ b/core/subsurface-qt/CylinderObjectHelper.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "CylinderObjectHelper.h"
 #include "../helpers.h"
 
diff --git a/core/subsurface-qt/CylinderObjectHelper.h b/core/subsurface-qt/CylinderObjectHelper.h
index c523eee20..eb0e22b0c 100644
--- a/core/subsurface-qt/CylinderObjectHelper.h
+++ b/core/subsurface-qt/CylinderObjectHelper.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef CYLINDER_QOBJECT_H
 #define CYLINDER_QOBJECT_H
 
@@ -28,4 +29,4 @@ private:
 };
 
 	Q_DECLARE_METATYPE(CylinderObjectHelper *)
-#endif
\ No newline at end of file
+#endif
diff --git a/core/subsurface-qt/DiveObjectHelper.cpp b/core/subsurface-qt/DiveObjectHelper.cpp
index e77d3a186..0f3172195 100644
--- a/core/subsurface-qt/DiveObjectHelper.cpp
+++ b/core/subsurface-qt/DiveObjectHelper.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "DiveObjectHelper.h"
 
 #include <QDateTime>
diff --git a/core/subsurface-qt/DiveObjectHelper.h b/core/subsurface-qt/DiveObjectHelper.h
index 81887d356..83aea4841 100644
--- a/core/subsurface-qt/DiveObjectHelper.h
+++ b/core/subsurface-qt/DiveObjectHelper.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef DIVE_QOBJECT_H
 #define DIVE_QOBJECT_H
 
diff --git a/core/subsurface-qt/SettingsObjectWrapper.cpp b/core/subsurface-qt/SettingsObjectWrapper.cpp
index a22b0c015..2752567ae 100644
--- a/core/subsurface-qt/SettingsObjectWrapper.cpp
+++ b/core/subsurface-qt/SettingsObjectWrapper.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "SettingsObjectWrapper.h"
 #include <QSettings>
 #include <QApplication>
diff --git a/core/subsurface-qt/SettingsObjectWrapper.h b/core/subsurface-qt/SettingsObjectWrapper.h
index 51cf4b0ae..bb0e9db62 100644
--- a/core/subsurface-qt/SettingsObjectWrapper.h
+++ b/core/subsurface-qt/SettingsObjectWrapper.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef SETTINGSOBJECTWRAPPER_H
 #define SETTINGSOBJECTWRAPPER_H
 
diff --git a/core/subsurfacesysinfo.cpp b/core/subsurfacesysinfo.cpp
index a7173b169..6f63a3011 100644
--- a/core/subsurfacesysinfo.cpp
+++ b/core/subsurfacesysinfo.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: LGPL-2.1+
 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
diff --git a/core/subsurfacesysinfo.h b/core/subsurfacesysinfo.h
index b2c267b83..f88229abb 100644
--- a/core/subsurfacesysinfo.h
+++ b/core/subsurfacesysinfo.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: LGPL-2.1+
 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
diff --git a/core/taxonomy.c b/core/taxonomy.c
index 65de11331..228020ae1 100644
--- a/core/taxonomy.c
+++ b/core/taxonomy.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "taxonomy.h"
 #include "gettext.h"
 #include <stdlib.h>
diff --git a/core/taxonomy.h b/core/taxonomy.h
index 51245d562..9fa9c6a0c 100644
--- a/core/taxonomy.h
+++ b/core/taxonomy.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef TAXONOMY_H
 #define TAXONOMY_H
 
diff --git a/core/units.h b/core/units.h
index f2557ed22..c92c23d3a 100644
--- a/core/units.h
+++ b/core/units.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef UNITS_H
 #define UNITS_H
 
diff --git a/core/version.c b/core/version.c
index 764e4d2db..c77f68e7a 100644
--- a/core/version.c
+++ b/core/version.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "ssrf-version.h"
 
 const char *subsurface_git_version(void)
diff --git a/core/webservice.h b/core/webservice.h
index 052b8aae7..1675a1743 100644
--- a/core/webservice.h
+++ b/core/webservice.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef WEBSERVICE_H
 #define WEBSERVICE_H
 
diff --git a/core/windowtitleupdate.cpp b/core/windowtitleupdate.cpp
index 963455f1d..810acd4dc 100644
--- a/core/windowtitleupdate.cpp
+++ b/core/windowtitleupdate.cpp
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "windowtitleupdate.h"
 
 WindowTitleUpdate *WindowTitleUpdate::m_instance = NULL;
diff --git a/core/windowtitleupdate.h b/core/windowtitleupdate.h
index 8650e5868..dcda821e9 100644
--- a/core/windowtitleupdate.h
+++ b/core/windowtitleupdate.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #ifndef WINDOWTITLEUPDATE_H
 #define WINDOWTITLEUPDATE_H