diff --git a/Engine/utility/textcodec.cpp b/Engine/utility/textcodec.cpp
index 9239ca63..449c13e3 100644
--- a/Engine/utility/textcodec.cpp
+++ b/Engine/utility/textcodec.cpp
@@ -43,6 +43,8 @@ std::u16string TextCodec::toUtf16(std::string_view inS) {
   for(size_t i=0; i<inS.size();) {
     uint32_t cp = 0;
     size_t   l  = Detail::utf8ToCodepoint(&s[i],cp);
+    if(l==0)
+      throw std::range_error("invalid utf-8"); // similar to stl
 
     if(cp > 0xFFFF)
       sz+=2; else
diff --git a/Tests/tests/textcodec_test.cpp b/Tests/tests/textcodec_test.cpp
index ef84213e..dfafc10b 100644
--- a/Tests/tests/textcodec_test.cpp
+++ b/Tests/tests/textcodec_test.cpp
@@ -56,3 +56,8 @@ TEST(main,TextCodec_UTF8_4) {
 
   TextCodec_Base(u8,u16);
   }
+
+TEST(main,TextCodec_UTF8_invalid) {
+  std::string u8 = "\340\214\244\276m\177\000\000\200\002\000\000h\001\000";
+  EXPECT_ANY_THROW(TextCodec::toUtf16(u8));
+  }