diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index 5e6363f..23ab5ae 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -71,6 +71,10 @@
     unsigned long long  st_ino;
 };
 
+extern int    chmod(const char *, mode_t);
+extern int    fchmod(int, mode_t);
+extern int    mkdir(const char *, mode_t);
+
 extern int    stat(const char *, struct stat *);
 extern int    fstat(int, struct stat *);
 extern int    lstat(const char *, struct stat *);
diff --git a/libc/include/sys/time.h b/libc/include/sys/time.h
index 4dee4da..1f010d4 100644
--- a/libc/include/sys/time.h
+++ b/libc/include/sys/time.h
@@ -56,7 +56,7 @@
 #define timeradd(a, b, res)                           \
     do {                                              \
         (res)->tv_sec  = (a)->tv_sec  + (b)->tv_sec;  \
-        (res)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
+        (res)->tv_usec = (a)->tv_usec + (b)->tv_usec; \
         if ((res)->tv_usec >= 1000000) {              \
             (res)->tv_usec -= 1000000;                \
             (res)->tv_sec  += 1;                      \
diff --git a/libc/include/sys/types.h b/libc/include/sys/types.h
index 92b452c..b071ee9 100644
--- a/libc/include/sys/types.h
+++ b/libc/include/sys/types.h
@@ -65,6 +65,7 @@
 #define _OFF_T_DEFINED_
 typedef __kernel_off_t       off_t;
 typedef __kernel_loff_t      loff_t;
+typedef loff_t               off64_t;  /* GLibc-specific */
 
 typedef __kernel_pid_t		 pid_t;