2 files changed, 2 insertions, 1 deletions
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index ac547c7..92442ac 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -1,4 +1,4 @@
-int printf(const char* fmt, ...);
+int printf(const char* fmt, ...)  __attribute__ ((format (printf, 1, 2)));;
 int puts(const char*);
 int putchar(int);
 
diff --git a/libc/include/string.h b/libc/include/string.h
index 650a7ac..05050a0 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -1,3 +1,4 @@
 #include <stddef.h>
 int strlen(const char*);
 void* memset(void*, int, size_t);
+void* memcpy(void*, void*, size_t);