diff --git a/lib/libc/include/sys/types.h b/lib/libc/include/sys/types.h
index 535e7dc..72577d9 100644
--- a/lib/libc/include/sys/types.h
+++ b/lib/libc/include/sys/types.h
@@ -8,6 +8,8 @@
 #define SEEK_END 2
 
 typedef size_t ino_t;
+typedef long pid_t;
+typedef long mode_t;
 
 struct dentry {
 	unsigned long d_ino;
diff --git a/lib/libc/include/unistd.h b/lib/libc/include/unistd.h
index b7f2365..269b71c 100644
--- a/lib/libc/include/unistd.h
+++ b/lib/libc/include/unistd.h
@@ -14,4 +14,13 @@ extern off_t lseek(int fd, off_t offset, int whence);
 
 extern long getdents(int fd, struct dentry *dirp, unsigned int count);
 
+extern pid_t fork(void);
+
+extern int execl(const char *path, const char *arg, ...);
+extern int execlp(const char *file, const char *arg, ...);
+extern int execle(const char *path, const char *arg, ...);
+extern int execv(const char *path, char *const argv[]);
+extern int execvp(const char *file, char *const argv[]);
+extern int execvpe(const char *file, char *const argv[], char *const envp[]);
+
 #endif