diff --git a/src/api/api_seq.cpp b/src/api/api_seq.cpp
index d64589cde..6a9d0f81c 100644
--- a/src/api/api_seq.cpp
+++ b/src/api/api_seq.cpp
@@ -212,6 +212,8 @@ extern "C" {
                 buffer.push_back('\\');
                 buffer.push_back('u');
                 buffer.push_back('{');
+                if (ch == 0)
+                    buff.push_back('0');
                 while (ch > 0) {
                     unsigned d = ch & 0xF;
                     if (d < 10)