diff --git a/src/yajl/yajl_encode.c b/src/yajl/yajl_encode.c
index 1a62aaf..e9e2aae 100644
--- a/src/yajl/yajl_encode.c
+++ b/src/yajl/yajl_encode.c
@@ -139,8 +139,8 @@ void yajl_string_decode(yajl_buf buf, const unsigned char * str,
                     end+=3;
                     /* check if this is a surrogate */
                     if ((codepoint & 0xFC00) == 0xD800) {
-                        end++;
-                        if (str[end] == '\\' && str[end + 1] == 'u') {
+                        if (end + 2 < len && str[end + 1] == '\\' && str[end + 2] == 'u') {
+                            end++;
                             unsigned int surrogate = 0;
                             hexToDigit(&surrogate, str + end + 2);
                             codepoint =