diff --git a/src/include/string.h b/src/include/string.h
index c3359807..745be2d6 100644
--- a/src/include/string.h
+++ b/src/include/string.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: string.h,v 1.14 2004/06/20 17:47:07 avsm Exp $	*/
+/*	$OpenBSD: string.h,v 1.15 2005/03/30 03:04:16 deraadt Exp $	*/
 /*	$NetBSD: string.h,v 1.6 1994/10/26 00:56:30 cgd Exp $	*/
 
 /*-
@@ -101,6 +101,7 @@ void	*memccpy(void *, const void *, int, size_t)
 char	*rindex(const char *, int);
 int	 strcasecmp(const char *, const char *);
 char	*strdup(const char *);
+char	*strcasestr(const char *, const char *);
 size_t	 strlcat(char *, const char *, size_t)
 		__attribute__ ((__bounded__(__string__,1,3)));
 size_t	 strlcpy(char *, const char *, size_t)
diff --git a/src/lib/libc/string/Makefile.inc b/src/lib/libc/string/Makefile.inc
index 902cf83c..81be9cea 100644
--- a/src/lib/libc/string/Makefile.inc
+++ b/src/lib/libc/string/Makefile.inc
@@ -1,11 +1,11 @@
-#	$OpenBSD: Makefile.inc,v 1.13 2004/05/03 19:56:08 millert Exp $
+#	$OpenBSD: Makefile.inc,v 1.14 2005/03/30 03:04:19 deraadt Exp $
 
 # string sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_ARCH}/string ${LIBCSRCDIR}/string
 
-SRCS+=	bm.c memccpy.c strcasecmp.c strcoll.c strdup.c strerror.c \
-	strerror_r.c strlcat.c strmode.c strsignal.c strtok.c strxfrm.c \
-	__strsignal.c
+SRCS+=	bm.c memccpy.c strcasecmp.c strcasestr.c strcoll.c strdup.c \
+	strerror.c strerror_r.c strlcat.c strmode.c strsignal.c strtok.c \
+	strxfrm.c __strsignal.c
 
 # machine-dependent net sources
 # m-d Makefile.inc must include sources for:
@@ -148,5 +148,6 @@ MLINKS+=strcat.3 strncat.3
 MLINKS+=strcmp.3 strncmp.3
 MLINKS+=strcpy.3 strncpy.3
 MLINKS+=strlcpy.3 strlcat.3
+MLINKS+=strstr.3 strcasestr.3
 MLINKS+=strtok.3 strtok_r.3
 MLINKS+=strerror.3 strerror_r.3
diff --git a/src/lib/libc/string/strcasestr.c b/src/lib/libc/string/strcasestr.c
new file mode 100644
index 00000000..075e6f19
--- /dev/null
+++ b/src/lib/libc/string/strcasestr.c
@@ -0,0 +1,64 @@
+/*	$OpenBSD: strcasestr.c,v 1.1 2005/03/30 03:04:19 deraadt Exp $	*/
+/*	$NetBSD: strcasestr.c,v 1.2 2005/02/09 21:35:47 kleink Exp $	*/
+
+/*-
+ * 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. 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = "$OpenBSD: strcasestr.c,v 1.1 2005/03/30 03:04:19 deraadt Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <ctype.h>
+#include <string.h>
+
+/*
+ * Find the first occurrence of find in s, ignore case.
+ */
+char *
+strcasestr(const char *s, const char *find)
+{
+	char c, sc;
+	size_t len;
+
+	if ((c = *find++) != 0) {
+		c = tolower((unsigned char)c);
+		len = strlen(find);
+		do {
+			do {
+				if ((sc = *s++) == 0)
+					return (NULL);
+			} while ((char)tolower((unsigned char)sc) != c);
+		} while (strncasecmp(s, find, len) != 0);
+		s--;
+	}
+	return ((char *)s);
+}
diff --git a/src/lib/libc/string/strstr.3 b/src/lib/libc/string/strstr.3
index 64396e78..2c8fa188 100644
--- a/src/lib/libc/string/strstr.3
+++ b/src/lib/libc/string/strstr.3
@@ -29,18 +29,20 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: strstr.3,v 1.7 2005/02/25 03:12:44 cloder Exp $
+.\"	$OpenBSD: strstr.3,v 1.8 2005/03/30 03:04:19 deraadt Exp $
 .\"
 .Dd June 29, 1991
 .Dt STRSTR 3
 .Os
 .Sh NAME
-.Nm strstr
+.Nm strstr , strcasestr
 .Nd locate a substring in a string
 .Sh SYNOPSIS
 .Fd #include <string.h>
 .Ft char *
 .Fn strstr "const char *big" "const char *little"
+.Ft char *
+.Fn strcasestr "const char *big" "const char *little"
 .Sh DESCRIPTION
 The
 .Fn strstr
@@ -48,23 +50,27 @@ function locates the first occurrence of the NUL-terminated string
 .Fa little
 in the NUL-terminated string
 .Fa big .
+.Pp
+The
+.Fn strcasestr
+function is similar to
+.Fn strstr
+but ignores the case of both strings.
+.Pp
 If
 .Fa little
-is the empty string,
-.Fn strstr
-returns
-.Fa big ;
+is an empty string,
+.Fa big
+is returned;
 if
 .Fa little
 occurs nowhere in
 .Fa big ,
-.Fn strstr
-returns
-.Dv NULL ;
-otherwise
-.Fn strstr
-returns a pointer to the first character of the first occurrence of
-.Fa little .
+.Dv NULL
+is returned;
+otherwise a pointer to the first character of the first occurrence of
+.Fa little
+is returned.
 .Sh SEE ALSO
 .Xr memchr 3 ,
 .Xr strchr 3 ,