diff --git a/programs/develop/ktcc/trunk/libc.obj/samples/malloc_test.c b/programs/develop/ktcc/trunk/libc.obj/samples/malloc_test.c
index ef53d4a5c..17a8b5ca4 100644
--- a/programs/develop/ktcc/trunk/libc.obj/samples/malloc_test.c
+++ b/programs/develop/ktcc/trunk/libc.obj/samples/malloc_test.c
@@ -136,7 +136,7 @@ bool check_buffer(void* ptr, size_t size, unsigned char pattern)
     unsigned char* byte_ptr = (unsigned char*)ptr;
     for (size_t i = 0; i < size; ++i) {
         if (byte_ptr[i] != pattern) {
-            fprintf(stderr, "Error: Byte %zu does not match pattern. Expected %02X, got %02X\n",
+            fprintf(stderr, "Error: Byte %u does not match pattern. Expected %02X, got %02X\n",
                 i, pattern, byte_ptr[i]);
             return false;
         }
diff --git a/programs/develop/ktcc/trunk/libc.obj/source/stdlib/free.c b/programs/develop/ktcc/trunk/libc.obj/source/stdlib/free.c
index 996929a26..a8760e494 100644
--- a/programs/develop/ktcc/trunk/libc.obj/source/stdlib/free.c
+++ b/programs/develop/ktcc/trunk/libc.obj/source/stdlib/free.c
@@ -1,3 +1,9 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-only
+ * Copyright (C) 2026 KolibriOS team
+ * Author: Yarin Egor<y.yarin@inbox.ru>
+ */
+
 #include <stdlib.h>
 #include <stdbool.h>
 #include <sys/ksys.h>
diff --git a/programs/develop/ktcc/trunk/libc.obj/source/stdlib/malloc.c b/programs/develop/ktcc/trunk/libc.obj/source/stdlib/malloc.c
index baf7daf2a..3fdc8619d 100644
--- a/programs/develop/ktcc/trunk/libc.obj/source/stdlib/malloc.c
+++ b/programs/develop/ktcc/trunk/libc.obj/source/stdlib/malloc.c
@@ -1,3 +1,9 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-only
+ * Copyright (C) 2026 KolibriOS team
+ * Author: Yarin Egor<y.yarin@inbox.ru>
+ */
+
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
diff --git a/programs/develop/ktcc/trunk/libc.obj/source/stdlib/realloc.c b/programs/develop/ktcc/trunk/libc.obj/source/stdlib/realloc.c
index 18c747e22..9a471bc6a 100644
--- a/programs/develop/ktcc/trunk/libc.obj/source/stdlib/realloc.c
+++ b/programs/develop/ktcc/trunk/libc.obj/source/stdlib/realloc.c
@@ -1,3 +1,9 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-only
+ * Copyright (C) 2026 KolibriOS team
+ * Author: Yarin Egor<y.yarin@inbox.ru>
+ */
+
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ksys.h>