diff --git a/system/include/libc/sys/_default_fcntl.h b/system/include/libc/sys/_default_fcntl.h
index 0f2ffb076..188e25c45 100644
--- a/system/include/libc/sys/_default_fcntl.h
+++ b/system/include/libc/sys/_default_fcntl.h
@@ -209,6 +209,11 @@ extern int _open64 _PARAMS ((const char *, int, ...));
 #define POSIX_FADV_DONTNEED 135
 int posix_fadvise(int fd, off_t offset, off_t len, int advice);
 int posix_fallocate(int fd, off_t offset, off_t len);
+#define LOCK_SH 1
+#define LOCK_EX 2
+#define LOCK_UN 4
+#define LOCK_NB 8
+int flock(int fd, int operation);
 
 #ifdef __cplusplus
 }
diff --git a/system/include/libc/sys/dirent.h b/system/include/libc/sys/dirent.h
index 1fbe2b21d..9dcf34d1e 100644
--- a/system/include/libc/sys/dirent.h
+++ b/system/include/libc/sys/dirent.h
@@ -26,6 +26,10 @@ long  telldir(DIR *);
 DIR  *readdir(DIR *);
 int   closedir(DIR *dirp);
 void  rewinddir(DIR *dirp);
+int   scandir(const char *dirp,
+              struct dirent ***namelist,
+              int (*filter)(const struct dirent *),
+              int (*compar)(const struct dirent **, const struct dirent **));
 
 enum {
   DT_UNKNOWN = 0,
diff --git a/system/include/sys/statvfs.h b/system/include/sys/statvfs.h
index cf0a8c96e..192be153e 100644
--- a/system/include/sys/statvfs.h
+++ b/system/include/sys/statvfs.h
@@ -20,7 +20,7 @@ struct statvfs {
   int f_namemax;
 };
 
-int statvfs(char *path, struct statvfs *s);
+int statvfs(const char *path, struct statvfs *s);
 
 #ifdef __cplusplus
 }