diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index dac2d2e29b..5fc4ca5b0b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -30524,7 +30524,7 @@ namespace ts {
             }
             else if (node.operator === SyntaxKind.ReadonlyKeyword) {
                 if (node.type.kind !== SyntaxKind.ArrayType && node.type.kind !== SyntaxKind.TupleType) {
-                    return grammarErrorOnFirstToken(node, Diagnostics.readonly_type_modifier_is_only_permitted_on_array_and_typle_types, tokenToString(SyntaxKind.SymbolKeyword));
+                    return grammarErrorOnFirstToken(node, Diagnostics.readonly_type_modifier_is_only_permitted_on_array_and_tuple_types, tokenToString(SyntaxKind.SymbolKeyword));
                 }
             }
         }
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index e0ac3eb77f..9d2f251e10 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1023,7 +1023,7 @@
         "category": "Error",
         "code": 1353
     },
-    "'readonly' type modifier is only permitted on array and typle types.": {
+    "'readonly' type modifier is only permitted on array and tuple types.": {
         "category": "Error",
         "code": 1354
     },