diff --git a/src/kernel/libroot/posix/stdio/Jamfile b/src/kernel/libroot/posix/stdio/Jamfile
index e871327c95..80271420df 100644
--- a/src/kernel/libroot/posix/stdio/Jamfile
+++ b/src/kernel/libroot/posix/stdio/Jamfile
@@ -40,6 +40,7 @@ KernelMergeObject posix_stdio.o :
 	<$(SOURCE_GRIST)>vfprintf.c
 	<$(SOURCE_GRIST)>vfscanf.c
 	<$(SOURCE_GRIST)>vscanf.c
+ 	<$(SOURCE_GRIST)>vsnprintf.c
  	<$(SOURCE_GRIST)>vsprintf.c
 	<$(SOURCE_GRIST)>wbuf.c
 	<$(SOURCE_GRIST)>wsetup.c
diff --git a/src/kernel/libroot/posix/stdio/vsnprintf.c b/src/kernel/libroot/posix/stdio/vsnprintf.c
new file mode 100644
index 0000000000..d0c8cfea55
--- /dev/null
+++ b/src/kernel/libroot/posix/stdio/vsnprintf.c
@@ -0,0 +1,55 @@
+/* Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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 REGENTS 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.
+ */
+
+
+#include <stdio.h>
+
+
+int
+vsnprintf(char *buffer, size_t bufferSize, const char *format, va_list ap)
+{
+	int bytesWritten;
+	FILE file;
+
+	file._file = -1;
+	file._flags = __SWR | __SSTR;
+	file._bf._base = file._p = (unsigned char *)buffer;
+	file._bf._size = file._w = bufferSize;
+	bytesWritten = vfprintf(&file, format, ap);
+	*file._p = '\0';
+
+	return bytesWritten;
+}
+