diff --git a/ets2panda/parser/ETSparserExpressions.cpp b/ets2panda/parser/ETSparserExpressions.cpp
index 7c0bd342e97a317106119b561437caf824eb9ed6..9763da93e64c6202c785b53644755927a4e6d561 100644
--- a/ets2panda/parser/ETSparserExpressions.cpp
+++ b/ets2panda/parser/ETSparserExpressions.cpp
@@ -584,7 +584,10 @@ ir::Expression *ETSParser::ParsePotentialAsExpression(ir::Expression *primaryExp
 {
     ES2PANDA_ASSERT(Lexer()->GetToken().Type() == lexer::TokenType::KEYW_AS);
     Lexer()->NextToken();
-
+    if (Lexer()->GetToken().Type() == lexer::TokenType::KEYW_CONST) {
+        LogError(diagnostic::AS_CONST_USAGE);
+        return nullptr;
+    }
     TypeAnnotationParsingOptions options =
         TypeAnnotationParsingOptions::REPORT_ERROR | TypeAnnotationParsingOptions::ANNOTATION_NOT_ALLOW;
     ir::TypeNode *type = ParseTypeAnnotation(&options);
diff --git a/ets2panda/test/ast/parser/ets/string_literal_const_cast.ets b/ets2panda/test/ast/parser/ets/string_literal_const_cast.ets
index 899f906944c3522294dfcdd5cb5f2c9b43feada2..d265e8555759d3a03bc205f29f3fe93f97c5d11f 100644
--- a/ets2panda/test/ast/parser/ets/string_literal_const_cast.ets
+++ b/ets2panda/test/ast/parser/ets/string_literal_const_cast.ets
@@ -15,7 +15,7 @@
 
 let x = "literal str" as const
 
-/* @@? 16:26 Error SyntaxError: Invalid Type. */
+/* @@? 16:26 Error SyntaxError: 'as const' assertion is not supported. */
 /* @@? 16:26 Error SyntaxError: Unexpected token 'const'. */
 /* @@? 23:1 Error SyntaxError: Identifier expected, got 'end of stream'. */
 /* @@? 23:1 Error SyntaxError: Variable must be initialized or it's type must be declared. */
diff --git a/ets2panda/util/diagnostic/syntax.yaml b/ets2panda/util/diagnostic/syntax.yaml
index a412c35ab549ada14459b3f41c431bdf0075ed09..864602db43dd4ab9980bc3a7edca0ad15f25e34f 100644
--- a/ets2panda/util/diagnostic/syntax.yaml
+++ b/ets2panda/util/diagnostic/syntax.yaml
@@ -1230,4 +1230,8 @@ syntax:
 
 - name: DEEP_NESTING
   id: 305
-  message: "Maximum allowed nesting level exceeded."
\ No newline at end of file
+  message: "Maximum allowed nesting level exceeded."
+
+- name: AS_CONST_USAGE
+  id: 306
+  message: "'as const' assertion is not supported."
\ No newline at end of file