diff --git a/.github/workflows/why2-core-test.yml b/.github/workflows/why2-core-test.yml
index 6471b4d..352fb81 100644
--- a/.github/workflows/why2-core-test.yml
+++ b/.github/workflows/why2-core-test.yml
@@ -1,3 +1,19 @@
+# This is part of WHY2
+# Copyright (C) 2022 Václav Šmejkal
+
+# 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/>.
+
 name: Test WHY2-core
 
 on:
diff --git a/.github/workflows/why2-logger-test.yml b/.github/workflows/why2-logger-test.yml
index 3ff33ec..8cd8db7 100644
--- a/.github/workflows/why2-logger-test.yml
+++ b/.github/workflows/why2-logger-test.yml
@@ -1,3 +1,19 @@
+# This is part of WHY2
+# Copyright (C) 2022 Václav Šmejkal
+
+# 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/>.
+
 name: Test WHY2-logger
 
 on:
diff --git a/.github/workflows/why2-project.yml b/.github/workflows/why2-project.yml
index f3742eb..c2e294e 100644
--- a/.github/workflows/why2-project.yml
+++ b/.github/workflows/why2-project.yml
@@ -1,3 +1,19 @@
+# This is part of WHY2
+# Copyright (C) 2022 Václav Šmejkal
+
+# 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/>.
+
 name: Test Project
 
 on:
diff --git a/Makefile b/Makefile
index 40fef96..13c7e5f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,19 @@
+# This is part of WHY2
+# Copyright (C) 2022 Václav Šmejkal
+
+# 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/>.
+
 # Compiler Settings
 CC=cc
 CFLAGS=-Wall -Wextra -Werror -Wcomment -Wformat -Wformat-security -Wmain -Wnonnull -Wunused -std=gnu11
diff --git a/configure.sh b/configure.sh
index 1c69076..4203841 100644
--- a/configure.sh
+++ b/configure.sh
@@ -1,5 +1,21 @@
 #!/bin/bash
 
+# This is part of WHY2
+# Copyright (C) 2022 Václav Šmejkal
+
+# 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/>.
+
 # Get linux distro
 DISTRO=$(lsb_release -is)
 
diff --git a/include/decrypter.h b/include/decrypter.h
index 56425de..eac014f 100644
--- a/include/decrypter.h
+++ b/include/decrypter.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_DECRYPTER_H
 #define WHY2_DECRYPTER_H
 
diff --git a/include/encrypter.h b/include/encrypter.h
index 5bdf943..b4b39ca 100644
--- a/include/encrypter.h
+++ b/include/encrypter.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_ENCRYPTER_H
 #define WHY2_ENCRYPTER_H
 
diff --git a/include/flags.h b/include/flags.h
index f901bde..1ee5b93 100644
--- a/include/flags.h
+++ b/include/flags.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_FLAGS_H
 #define WHY2_FLAGS_H
 
diff --git a/include/logger/flags.h b/include/logger/flags.h
index 429641e..36fcdb3 100644
--- a/include/logger/flags.h
+++ b/include/logger/flags.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_LOGGER_FLAGS_H
 #define WHY2_LOGGER_FLAGS_H
 
diff --git a/include/logger/logger.h b/include/logger/logger.h
index 57872d4..ee0ff6a 100644
--- a/include/logger/logger.h
+++ b/include/logger/logger.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_LOGGER_LOGGER_H
 #define WHY2_LOGGER_LOGGER_H
 
diff --git a/include/logger/utils.h b/include/logger/utils.h
index bfe7fdf..19d7ff8 100644
--- a/include/logger/utils.h
+++ b/include/logger/utils.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_LOGGER_UTILS_C
 #define WHY2_LOGGER_UTILS_C
 
diff --git a/include/misc.h b/include/misc.h
index 5f86901..639e8c6 100644
--- a/include/misc.h
+++ b/include/misc.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #ifndef WHY2_MISC_H
 #define WHY2_MISC_H
 
diff --git a/include/why2.h b/include/why2.h
index 0198ec7..00bc93a 100644
--- a/include/why2.h
+++ b/include/why2.h
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 /*
     This file basically contains all header files that are needed to use WHY2.
 
diff --git a/src/core/app/main.c b/src/core/app/main.c
index 3ceb798..fb4b4a6 100644
--- a/src/core/app/main.c
+++ b/src/core/app/main.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <stdio.h>
 
 #include <why2.h>
diff --git a/src/core/lib/decrypter.c b/src/core/lib/decrypter.c
index f2a1118..9798904 100644
--- a/src/core/lib/decrypter.c
+++ b/src/core/lib/decrypter.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <why2/decrypter.h>
 
 #include <stdio.h>
diff --git a/src/core/lib/encrypter.c b/src/core/lib/encrypter.c
index 3150cdc..ffd75dc 100644
--- a/src/core/lib/encrypter.c
+++ b/src/core/lib/encrypter.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <why2/encrypter.h>
 
 #include <stdio.h>
diff --git a/src/core/lib/flags.c b/src/core/lib/flags.c
index a78f492..5a4ba93 100644
--- a/src/core/lib/flags.c
+++ b/src/core/lib/flags.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <why2/flags.h>
 
 #include <stdlib.h>
diff --git a/src/core/lib/misc.c b/src/core/lib/misc.c
index 7ca0ee6..1fc8e62 100644
--- a/src/core/lib/misc.c
+++ b/src/core/lib/misc.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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/>.
+*/
+
 #define _XOPEN_SOURCE 500
 
 #include <why2/misc.h>
diff --git a/src/core/lib/test/main.c b/src/core/lib/test/main.c
index f1f71be..8a2c3db 100644
--- a/src/core/lib/test/main.c
+++ b/src/core/lib/test/main.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/logger/lib/logger.c b/src/logger/lib/logger.c
index 121563c..c2be6ef 100644
--- a/src/logger/lib/logger.c
+++ b/src/logger/lib/logger.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <why2/logger/logger.h>
 
 #include <stdio.h>
diff --git a/src/logger/lib/test/main.c b/src/logger/lib/test/main.c
index d3f8ea8..bd5daaa 100644
--- a/src/logger/lib/test/main.c
+++ b/src/logger/lib/test/main.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <why2.h>
 
 #include <stdio.h>
diff --git a/src/logger/lib/utils.c b/src/logger/lib/utils.c
index fda5b17..f0aaf8f 100644
--- a/src/logger/lib/utils.c
+++ b/src/logger/lib/utils.c
@@ -1,3 +1,21 @@
+/*
+This is part of WHY2
+Copyright (C) 2022 Václav Šmejkal
+
+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 <why2/logger/utils.h>
 
 #include <unistd.h>