diff --git a/configure.ac b/configure.ac
index 18d8ab5ff..8f2a96652 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1006,6 +1006,8 @@ AC_CHECK_FUNC(strcasecmp, [], AC_DEFINE([NEED_STRCASECMP], 1,
                                         [Do not have 'strcasecmp'.]))
 AC_CHECK_FUNC(strncasecmp, [], AC_DEFINE([NEED_STRNCASECMP], 1,
                                         [Do not have 'strncasecmp'.]))
+AC_CHECK_FUNC(strcasestr, [], AC_DEFINE([NEED_STRCASESTR], 1,
+                                       [Do not have 'strcasestr'.]))
 
 if test "x$NULL_ROOT_CURSOR" = xyes; then
         AC_DEFINE(NULL_ROOT_CURSOR, 1, [Use an empty root cursor])
diff --git a/dix/Makefile.am b/dix/Makefile.am
index c8718e4a6..45da45fcb 100644
--- a/dix/Makefile.am
+++ b/dix/Makefile.am
@@ -36,7 +36,8 @@ libdix_la_SOURCES = 	\
 	swapreq.c	\
 	tables.c	\
 	window.c	\
-	strcasecmp.c
+	strcasecmp.c	\
+	strcasestr.c
 
 EXTRA_DIST = buildatoms BuiltInAtoms CHANGES Xserver.d Xserver-dtrace.h.in
 
diff --git a/dix/strcasestr.c b/dix/strcasestr.c
new file mode 100644
index 000000000..b3d45495c
--- /dev/null
+++ b/dix/strcasestr.c
@@ -0,0 +1,64 @@
+/*-
+ * 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.
+ * 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.
+ */
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include <ctype.h>
+#include <string.h>
+#include "dix.h"
+
+/*
+ * Find the first occurrence of find in s, ignore case.
+ */
+#ifdef NEED_STRCASESTR
+char *
+xstrcasestr(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);
+}
+#endif
diff --git a/include/dix-config.h.in b/include/dix-config.h.in
index ed664a92c..06549183d 100644
--- a/include/dix-config.h.in
+++ b/include/dix-config.h.in
@@ -501,4 +501,7 @@
 /* Need the strncasecmp function. */
 #undef NEED_STRNCASECMP
 
+/* Need the strcasestr function. */
+#undef NEED_STRCASESTR
+
 #endif /* _DIX_CONFIG_H_ */
diff --git a/include/dix.h b/include/dix.h
index a8c2b3b5a..ac03ce0e9 100644
--- a/include/dix.h
+++ b/include/dix.h
@@ -609,6 +609,11 @@ extern int xstrcasecmp(const char *s1, const char *s2);
 extern int xstrncasecmp(const char *s1, const char *s2, size_t n);
 #endif
 
+#if NEED_STRCASESTR
+#define strcasestr xstrcasestr
+extern int xstrcasestr(const char *s, const char *find);
+#endif
+
 extern int XItoCoreType(int xi_type);
 extern Bool DevHasCursor(DeviceIntPtr pDev);
 extern Bool IsPointerDevice( DeviceIntPtr dev);