diff --git a/configure.in b/configure.in
index a0dd303..4c55e2a 100644
--- a/configure.in
+++ b/configure.in
@@ -1432,7 +1432,7 @@ AC_CHECK_FUNCS(fmod killpg wait4 waitpid fork spawnv syscall __syscall chroot ge
 	      setuid setgid daemon select_large_fdset setenv unsetenv\
               mktime timegm gmtime_r clock_gettime gettimeofday poll ppoll\
               pread sendfile shutdown sigaltstack dl_iterate_phdr\
-              dup3 pipe2 posix_memalign memalign)
+              dup3 pipe2 posix_memalign memalign memmem)
 
 AC_CACHE_CHECK(for unsetenv returns a value, rb_cv_unsetenv_return_value,
   [AC_TRY_COMPILE([
@@ -2733,6 +2733,40 @@ if test "${universal_binary-no}" = yes ; then
     ])])
 fi
 
+AC_CACHE_CHECK(for broken memmem, rb_cv_broken_memmem,
+  [AC_TRY_RUN([
+#include <string.h>
+
+int
+main()
+{
+  char *str = "hogefugafoobar";
+  char *rs = "foo";
+  char *empty = "";
+  char *p;
+
+  p = memmem(str, strlen(str), rs, strlen(rs));
+  if (p == str+8) {
+    p = memmem(str, strlen(str), empty, strlen(empty));
+    if (p == str)
+      return 0;
+    else
+      return 1;
+  }
+  else {
+    return 1;
+  }
+}
+  ],
+  rb_cv_broken_memmem=no,
+  rb_cv_broken_memmem=yes,
+  rb_cv_broken_memmem=yes)
+])
+
+if test "$rb_cv_broken_memmem" = yes; then
+  AC_DEFINE(BROKEN_MEMMEM, 1)
+fi
+
 CPPFLAGS="$CPPFLAGS "'$(DEFS)'
 test -z "$CPPFLAGS" || CPPFLAGS="$CPPFLAGS "; CPPFLAGS="$CPPFLAGS"'${cppflags}'
 if test -n "${cflags+set}"; then
diff --git a/re.c b/re.c
index 590e9b0..fb3f84d 100644
--- a/re.c
+++ b/re.c
@@ -228,7 +228,16 @@ rb_memsearch(const void *x0, long m, const void *y0, long n, rb_encoding *enc)
 	return -1;
     }
     else if (m <= SIZEOF_VALUE) {
+#if defined(HAVE_MEMMEM) && !defined(BROKEN_MEMMEM)
+	const unsigned char *ys;
+
+	if (ys = memmem(y, n, x, m))
+	    return ys - y;
+	else
+	    return -1;
+#else
 	return rb_memsearch_ss(x0, m, y0, n);
+#endif
     }
     else if (enc == rb_utf8_encoding()){
 	return rb_memsearch_qs_utf8(x0, m, y0, n);