diff --git a/src/lib_json/json_writer.cpp b/src/lib_json/json_writer.cpp
index ef976bfab..66ca21727 100644
--- a/src/lib_json/json_writer.cpp
+++ b/src/lib_json/json_writer.cpp
@@ -317,8 +317,14 @@ void FastWriter::writeValue(const Value& value) {
     document_ += valueToString(value.asDouble());
     break;
   case stringValue:
-    document_ += valueToQuotedString(value.asCString());
+  {
+    // Is NULL possible for value.string_?
+    char const* str;
+    char const* end;
+    bool ok = value.getString(&str, &end);
+    if (ok) document_ += valueToQuotedStringN(str, static_cast<unsigned>(end-str));
     break;
+  }
   case booleanValue:
     document_ += valueToString(value.asBool());
     break;
@@ -382,7 +388,7 @@ void StyledWriter::writeValue(const Value& value) {
     break;
   case stringValue:
   {
-    // Is NULL is possible for value.string_?
+    // Is NULL possible for value.string_?
     char const* str;
     char const* end;
     bool ok = value.getString(&str, &end);
@@ -599,8 +605,15 @@ void StyledStreamWriter::writeValue(const Value& value) {
     pushValue(valueToString(value.asDouble()));
     break;
   case stringValue:
-    pushValue(valueToQuotedString(value.asCString()));
+  {
+    // Is NULL possible for value.string_?
+    char const* str;
+    char const* end;
+    bool ok = value.getString(&str, &end);
+    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
+    else pushValue("");
     break;
+  }
   case booleanValue:
     pushValue(valueToString(value.asBool()));
     break;