diff --git a/src/parsing/literal-buffer.cc b/src/parsing/literal-buffer.cc
index c7e5560b960..d272fe760d0 100644
--- a/src/parsing/literal-buffer.cc
+++ b/src/parsing/literal-buffer.cc
@@ -45,6 +45,10 @@ void LiteralBuffer::ExpandBuffer() {
 
 void LiteralBuffer::ConvertToTwoByte() {
   DCHECK(is_one_byte());
+  // Bandaid for integer overflow: position_ * kUC16Size must not wrap. The
+  // streaming-compile path can drive position_ past String::kMaxLength, so
+  // this must be a release CHECK rather than a DCHECK.
+  CHECK_LE(position_, std::numeric_limits<int>::max() / base::kUC16Size);
   base::Vector<uint8_t> new_store;
   int new_content_size = position_ * base::kUC16Size;
   if (new_content_size >= backing_store_.length()) {