diff --git a/src/P700Printer.cpp b/src/P700Printer.cpp
index 13941fa..6d295e5 100644
--- a/src/P700Printer.cpp
+++ b/src/P700Printer.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "P700Printer.hpp"
 
 #include <spdlog/spdlog.h>
diff --git a/src/P700Printer.hpp b/src/P700Printer.hpp
index 34f09f8..4b54ef1 100644
--- a/src/P700Printer.hpp
+++ b/src/P700Printer.hpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include <sys/types.h>
 
 #include <map>
diff --git a/src/PtouchPrint.cpp b/src/PtouchPrint.cpp
index a2c8859..0fd7162 100644
--- a/src/PtouchPrint.cpp
+++ b/src/PtouchPrint.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "PtouchPrint.hpp"
 
 #include <spdlog/spdlog.h>
diff --git a/src/PtouchPrint.hpp b/src/PtouchPrint.hpp
index 141ef27..f8b5533 100644
--- a/src/PtouchPrint.hpp
+++ b/src/PtouchPrint.hpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #pragma once
 
 #include "interface/IPrinterDriver.hpp"
diff --git a/src/graphics/Bitmap.cpp b/src/graphics/Bitmap.cpp
index c9ae74c..ed283bc 100644
--- a/src/graphics/Bitmap.cpp
+++ b/src/graphics/Bitmap.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "Bitmap.hpp"
 
 #include <algorithm>
diff --git a/src/graphics/Bitmap.hpp b/src/graphics/Bitmap.hpp
index 422a880..eb30ec6 100644
--- a/src/graphics/Bitmap.hpp
+++ b/src/graphics/Bitmap.hpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #pragma once
 
 #include <stdint.h>
diff --git a/src/graphics/Image.cpp b/src/graphics/Image.cpp
index 44170dc..677199f 100644
--- a/src/graphics/Image.cpp
+++ b/src/graphics/Image.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "Image.hpp"
 
 #include "pango/pango-font.h"
diff --git a/src/graphics/Image.hpp b/src/graphics/Image.hpp
index be3a051..2302787 100644
--- a/src/graphics/Image.hpp
+++ b/src/graphics/Image.hpp
@@ -1,3 +1,24 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
+#pragma once
+
 #include <pango/pangocairo.h>
 
 #include <cstdint>
diff --git a/src/graphics/Monochrome.cpp b/src/graphics/Monochrome.cpp
index d8cae2c..596ccbc 100644
--- a/src/graphics/Monochrome.cpp
+++ b/src/graphics/Monochrome.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "graphics/Monochrome.hpp"
 
 #include <cmath>
diff --git a/src/graphics/Monochrome.hpp b/src/graphics/Monochrome.hpp
index 8186abc..b029de9 100644
--- a/src/graphics/Monochrome.hpp
+++ b/src/graphics/Monochrome.hpp
@@ -1,3 +1,24 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
+#pragma once
+
 #include <cstdint>
 
 #include "graphics/Bitmap.hpp"
diff --git a/src/interface/IPrinterDriver.hpp b/src/interface/IPrinterDriver.hpp
index 0fcede6..0a0ccda 100644
--- a/src/interface/IPrinterDriver.hpp
+++ b/src/interface/IPrinterDriver.hpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #pragma once
 
 #include <memory>
diff --git a/src/interface/IPrinterTypes.hpp b/src/interface/IPrinterTypes.hpp
index 216cdc8..9e6e66d 100644
--- a/src/interface/IPrinterTypes.hpp
+++ b/src/interface/IPrinterTypes.hpp
@@ -1,3 +1,21 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
 
 #pragma once
 
diff --git a/src/libusbwrap/LibUsbTypes.hpp b/src/libusbwrap/LibUsbTypes.hpp
index be13763..43977c0 100644
--- a/src/libusbwrap/LibUsbTypes.hpp
+++ b/src/libusbwrap/LibUsbTypes.hpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #pragma once
 
 #include <memory>
diff --git a/src/libusbwrap/UsbDevice.cpp b/src/libusbwrap/UsbDevice.cpp
index daeb994..8841561 100644
--- a/src/libusbwrap/UsbDevice.cpp
+++ b/src/libusbwrap/UsbDevice.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "libusbwrap/UsbDevice.hpp"
 
 #include <cstdint>
diff --git a/src/libusbwrap/UsbDevice.hpp b/src/libusbwrap/UsbDevice.hpp
index 972bfa7..ab922da 100644
--- a/src/libusbwrap/UsbDevice.hpp
+++ b/src/libusbwrap/UsbDevice.hpp
@@ -3,6 +3,27 @@
 #include <atomic>
 #include <cstddef>
 
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
+#pragma once
+
 #include "libusb.h"
 #include "libusbwrap/LibUsbTypes.hpp"
 #include "libusbwrap/interface/IUsbDevice.hpp"
diff --git a/src/libusbwrap/UsbDeviceFactory.cpp b/src/libusbwrap/UsbDeviceFactory.cpp
index ea5dc83..53a8695 100644
--- a/src/libusbwrap/UsbDeviceFactory.cpp
+++ b/src/libusbwrap/UsbDeviceFactory.cpp
@@ -1,3 +1,21 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
 
 #include "libusbwrap/UsbDeviceFactory.hpp"
 
diff --git a/src/libusbwrap/UsbDeviceFactory.hpp b/src/libusbwrap/UsbDeviceFactory.hpp
index 1f502db..db4c3fa 100644
--- a/src/libusbwrap/UsbDeviceFactory.hpp
+++ b/src/libusbwrap/UsbDeviceFactory.hpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #pragma once
 
 #include "libusbwrap/interface/IUsbDeviceFactory.hpp"
diff --git a/src/main.cpp b/src/main.cpp
index e4e4f83..525fe8a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include <spdlog/spdlog.h>
 
 #include "PtouchPrint.hpp"
diff --git a/tests/bitmap_test/bitmap_test.cpp b/tests/bitmap_test/bitmap_test.cpp
index 9480ab2..7707874 100644
--- a/tests/bitmap_test/bitmap_test.cpp
+++ b/tests/bitmap_test/bitmap_test.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "graphics/Bitmap.hpp"
 
 #include <gtest/gtest.h>
diff --git a/tests/image_test/image_test.cpp b/tests/image_test/image_test.cpp
index 24c1082..efa7cda 100644
--- a/tests/image_test/image_test.cpp
+++ b/tests/image_test/image_test.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "graphics/Image.hpp"
 
 #include <gtest/gtest.h>
diff --git a/tests/monochrome_test/monochrome_test.cpp b/tests/monochrome_test/monochrome_test.cpp
index e266aaf..74444ba 100644
--- a/tests/monochrome_test/monochrome_test.cpp
+++ b/tests/monochrome_test/monochrome_test.cpp
@@ -1,3 +1,22 @@
+/* 
+    ptrnt - print labels on linux
+    Copyright (C) 2023  Moritz Martinius
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+ */
+
 #include "graphics/Monochrome.hpp"
 
 #include <gtest/gtest.h>