diff --git a/src/plugin_crc16.c b/src/plugin_crc16.c
index afa27ae..ce59522 100644
--- a/src/plugin_crc16.c
+++ b/src/plugin_crc16.c
@@ -1,3 +1,33 @@
+/*
+ * Library: libcrc16
+ * File:    src/plugin_crc16.c
+ * Original Author: Lammert Bies
+ * Plugin Author:   Syping
+ *
+ * This file is licensed under the MIT License as stated below
+ *
+ * Copyright (c) 1999-2016 Lammert Bies
+ * Copyright (c) 2020 Syping
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
 #include "checksum.h"
 
 const char* checkbrute_format()
diff --git a/src/plugin_crc32.c b/src/plugin_crc32.c
index a39ef27..a7d6c07 100644
--- a/src/plugin_crc32.c
+++ b/src/plugin_crc32.c
@@ -1,3 +1,33 @@
+/*
+ * Library: libcrc32
+ * File:    src/plugin_crc32.c
+ * Original Author: Lammert Bies
+ * Plugin Author:   Syping
+ *
+ * This file is licensed under the MIT License as stated below
+ *
+ * Copyright (c) 1999-2016 Lammert Bies
+ * Copyright (c) 2020 Syping
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
 #include "checksum.h"
 
 const char* checkbrute_format()
diff --git a/src/plugin_jamcrc.c b/src/plugin_jamcrc.c
index 4c7fad5..1c97d8a 100644
--- a/src/plugin_jamcrc.c
+++ b/src/plugin_jamcrc.c
@@ -1,3 +1,33 @@
+/*
+ * Library: libjamcrc
+ * File:    src/plugin_jamcrc.c
+ * Original Author: Lammert Bies
+ * Plugin Author:   Syping
+ *
+ * This file is licensed under the MIT License as stated below
+ *
+ * Copyright (c) 1999-2016 Lammert Bies
+ * Copyright (c) 2020 Syping
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
 #include <stdbool.h>
 #include "checksum.h"
 
@@ -6,7 +36,6 @@ static bool crc_tab32_init = false;
 static uint32_t	crc_tab32[256];
 
 static void init_crc32_tab(void) {
-
     uint32_t i;
     uint32_t j;
     uint32_t crc;