diff --git a/cf/roken-frag.m4 b/cf/roken-frag.m4
index cbf9124e2..7c003bc7d 100644
--- a/cf/roken-frag.m4
+++ b/cf/roken-frag.m4
@@ -193,6 +193,7 @@ AC_CHECK_FUNCS([				\
 	getrlimit				\
 	getspnam				\
 	issetugid				\
+	memmem					\
 	on_exit					\
 	poll					\
 	random					\
diff --git a/lib/roken/Makefile.am b/lib/roken/Makefile.am
index d5c8546d8..602fd1f6e 100644
--- a/lib/roken/Makefile.am
+++ b/lib/roken/Makefile.am
@@ -102,6 +102,7 @@ libroken_la_SOURCES =		\
 	hex.c			\
 	hostent_find_fqdn.c	\
 	issuid.c		\
+	memmem.c		\
 	mini_inetd.c		\
 	mkdir.c                 \
 	net_read.c		\
diff --git a/lib/roken/NTMakefile b/lib/roken/NTMakefile
index 44ca1a0ba..bf4e95d89 100644
--- a/lib/roken/NTMakefile
+++ b/lib/roken/NTMakefile
@@ -73,6 +73,7 @@ libroken_la_OBJS =			\
 	$(OBJ)\issuid.obj		\
 	$(OBJ)\localtime_r.obj		\
 	$(OBJ)\lstat.obj		\
+	$(OBJ)\memmem.obj 		\
 	$(OBJ)\memset_s.obj 		\
 	$(OBJ)\mkdir.obj                \
 	$(OBJ)\mini_inetd.obj		\
diff --git a/lib/roken/memmem.c b/lib/roken/memmem.c
new file mode 100644
index 000000000..3f9c6bcfd
--- /dev/null
+++ b/lib/roken/memmem.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * 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 Institute 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 INSTITUTE 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 INSTITUTE 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 <config.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef HAVE_MEMMEM
+#include "roken.h"
+ROKEN_LIB_FUNCTION void * ROKEN_LIB_CALL
+memmem(const void *haystack,
+       size_t haystacklen,
+       const void *needle,
+       size_t needlelen)
+{
+  const unsigned char *hs = haystack;
+  const unsigned char *n = needle;
+  size_t hsi, ni;
+
+  if (haystacklen < needlelen || haystacklen == 0)
+      return NULL;
+  /*
+   * Imagine a haystack of length 5 and needle of length 2, then the largest
+   * index in the haystack at which we can bother looking for the needle is:
+   *
+   *    0 1 2 3 4
+   *   +---------+
+   *   |?|?|?|?|?|
+   *   +---------+
+   *          ^
+   *           \
+   *            here, at index 3, which is 5 - 2, and less than (5 - 2 + 1).
+   */
+  for (hsi = 0, ni = 0; hsi < (haystacklen - needlelen + 1); hsi++, ni = 0) {
+      while (ni < needlelen && n[ni] == hs[hsi + ni])
+          ni++;
+      if (ni == needlelen)
+          return rk_UNCONST(&hs[hsi]);
+  }
+  return NULL;
+}
+#endif
diff --git a/lib/roken/roken.h.in b/lib/roken/roken.h.in
index 2a3feb74a..47fe27812 100644
--- a/lib/roken/roken.h.in
+++ b/lib/roken/roken.h.in
@@ -446,6 +446,11 @@ rk_wcsdup(const unsigned short *);
 
 #endif  /* _MSC_VER */
 
+#ifndef HAVE_MEMMEM
+#define memmem rk_smemmem
+ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL memmem(const char *);
+#endif
+
 #ifdef HAVE_WINSOCK
 
 /* While we are at it, define WinSock specific scatter gather socket
diff --git a/lib/roken/version-script.map b/lib/roken/version-script.map
index 8f7e57ec2..5c0579249 100644
--- a/lib/roken/version-script.map
+++ b/lib/roken/version-script.map
@@ -83,6 +83,7 @@ HEIMDAL_ROKEN_2.0 {
 		rk_inet_pton;
 		rk_injectauxv;
 		rk_localtime_r;
+		rk_memmem;
 		rk_memset_s;
 		rk_mkdir;
 		rk_mkstemp;