diff --git a/auto-static.c b/auto-static.c
index cd636a9..68da3b8 100644
--- a/auto-static.c
+++ b/auto-static.c
@@ -381,9 +381,10 @@ static int valid_utf8_char (const char *str) {
   return n + 1;
 }
 
-static void print_escaped_string (const char *str) {
+static void print_escaped_string (const char *str, int len) {
   eprintf ("\"");
-  while (*str) {
+  const char *end = str + len;
+  while (str < end) {
     int n = valid_utf8_char (str);
     if (n < 0) {
       eprintf ("\\x%02x", (int)(unsigned char)*str);
diff --git a/generate.c b/generate.c
index 09b48c2..1f1eb49 100644
--- a/generate.c
+++ b/generate.c
@@ -832,7 +832,7 @@ void gen_constructor_fetch (struct tl_combinator *c) {
     printf ("  if (l < 0 || (l >= (1 << 22) - 2)) { return -1; }\n");
     printf ("  memcpy (buf, fetch_str (l), l);\n");
     printf ("  buf[l] = 0;\n");
-    printf ("  print_escaped_string (buf);\n");
+    printf ("  print_escaped_string (buf, l);\n");
     printf ("  return 0;\n");
     printf ("}\n");
     return;