diff --git a/vendor/github.com/cespare/xxhash/xxhash_safe.go b/vendor/github.com/cespare/xxhash/xxhash_safe.go
new file mode 100644
index 0000000..dfa15ab
--- /dev/null
+++ b/vendor/github.com/cespare/xxhash/xxhash_safe.go
@@ -0,0 +1,10 @@
+// +build appengine
+
+// This file contains the safe implementations of otherwise unsafe-using code.
+
+package xxhash
+
+// Sum64String computes the 64-bit xxHash digest of s.
+func Sum64String(s string) uint64 {
+	return Sum64([]byte(s))
+}