diff --git a/libc/bionic/memmem.cpp b/libc/bionic/memmem.cpp
new file mode 100644
index 0000000..61d681f
--- /dev/null
+++ b/libc/bionic/memmem.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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 <string.h>
+
+void* memmem(const void* void_haystack, size_t n, const void* void_needle, size_t m) {
+  const unsigned char* haystack = reinterpret_cast<const unsigned char*>(void_haystack);
+  const unsigned char* needle = reinterpret_cast<const unsigned char*>(void_needle);
+
+  if (n < m) return nullptr;
+
+  if (m == 0) return const_cast<void*>(void_haystack);
+  if (m == 1) return memchr(haystack, needle[0], n);
+
+  // This uses the "Not So Naive" algorithm, a very simple but usually effective algorithm.
+  // http://www-igm.univ-mlv.fr/~lecroq/string/
+  const unsigned char* y = haystack;
+  const unsigned char* x = needle;
+  size_t j = 0;
+  size_t k = 1, l = 2;
+
+  if (x[0] == x[1]) {
+    k = 2;
+    l = 1;
+  }
+  while (j <= n-m) {
+    if (x[1] != y[j+1]) {
+      j += k;
+    } else {
+      if (!memcmp(x+2, y+j+2, m-2) && x[0] == y[j]) return const_cast<unsigned char*>(&y[j]);
+      j += l;
+    }
+  }
+  return nullptr;
+}