diff --git a/hermit/include/sys/poll.h b/hermit/include/sys/poll.h
index 64502c558..32619b5a8 100644
--- a/hermit/include/sys/poll.h
+++ b/hermit/include/sys/poll.h
@@ -71,6 +71,10 @@ struct pollfd {
 	short revents;
 };
 
+typedef unsigned long int nfds_t;
+
+int poll(struct pollfd *fds, nfds_t nfds, int timeout);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/hermit/include/sys/uio.h b/hermit/include/sys/uio.h
new file mode 100644
index 000000000..159d5469a
--- /dev/null
+++ b/hermit/include/sys/uio.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2015, Stefan Lankes, RWTH Aachen University
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *    * Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *    * Neither the name of the University nor the names of its contributors
+ *      may be used to endorse or promote products derived from this
+ *      software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __SYS_MMAN_H__
+#define __SYS_MMAN_H__
+
+/**
+ * @author Stefan Lankes
+ * @file include/hermit/uio.h
+ * @brief Definition of struct iovec
+ */
+
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Structure for scatter/gather I/O. */
+struct iovec
+{
+	void *iov_base;	/* Pointer to data.  */
+	size_t iov_len;	/* Length of data.  */
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif