diff --git a/components/libc/compilers/armlibc/sys/unistd.h b/components/libc/compilers/armlibc/sys/unistd.h
index 524de2cf83..549771e8f4 100644
--- a/components/libc/compilers/armlibc/sys/unistd.h
+++ b/components/libc/compilers/armlibc/sys/unistd.h
@@ -68,4 +68,6 @@
 int     isatty      (int fd);
 char *  ttyname     (int desc);
 
+unsigned int sleep(unsigned int seconds);
+
 #endif /* _SYS_UNISTD_H */
diff --git a/components/libc/compilers/common/sys/time.h b/components/libc/compilers/common/sys/time.h
index 22f1c17f5e..952dbf32a5 100644
--- a/components/libc/compilers/common/sys/time.h
+++ b/components/libc/compilers/common/sys/time.h
@@ -36,6 +36,13 @@ struct timeval {
 };
 #endif /* _TIMEVAL_DEFINED */
 
+#ifndef _TIMESPEC
+#define _TIMESPEC
+struct timespec {
+    time_t  tv_sec;     /* seconds */
+    long    tv_nsec;    /* and nanoseconds */
+};
+#endif
 
 struct timezone {
   int tz_minuteswest;   /* minutes west of Greenwich */
diff --git a/components/libc/compilers/dlib/sys/unistd.h b/components/libc/compilers/dlib/sys/unistd.h
index 9564daba8d..982a29135d 100644
--- a/components/libc/compilers/dlib/sys/unistd.h
+++ b/components/libc/compilers/dlib/sys/unistd.h
@@ -40,4 +40,6 @@
 int     isatty      (int fd);
 char *  ttyname     (int desc);
 
+unsigned int sleep(unsigned int seconds);
+
 #endif /* _SYS_UNISTD_H */