diff --git a/src/services/codefixes/convertToUnknownFirst.ts b/src/services/codefixes/convertToUnknownFirst.ts
new file mode 100644
index 0000000000000..f4f0e20e4cdd5
--- /dev/null
+++ b/src/services/codefixes/convertToUnknownFirst.ts
@@ -0,0 +1,21 @@
+/* @internal */
+namespace ts.codefix {
+    const fixId = "convertToUnknownFirst";
+
+    const errorCodes = [Diagnostics.Conversion_of_type_0_to_type_1_may_be_a_mistake_because_neither_type_sufficiently_overlaps_with_the_other_If_this_was_intentional_convert_the_expression_to_unknown_first];
+    registerCodeFix({
+        errorCodes,
+        getCodeActions: (context) => {
+            const changes = textChanges.ChangeTracker.with(context, t => changeInferToUnknown(t, context.sourceFile, context.token));
+            return [createCodeFixAction(fixId, changes, Diagnostics.Replace_infer_0_with_unknown, fixId, Diagnostics.Replace_all_unused_infer_with_unknown];
+        },
+        fixIds: [fixId],
+        getAllCodeActions: context => codeFixAll(context, errorCodes, (changes, diag) => changeInferToUnknown(changes, diag.file, diag.start)),
+    });
+
+
+    // TODO how does codefix know which scenario to fire?
+    function changeInferToUnknown(changes: textChanges.ChangeTracker, sourceFile: SourceFile, token: Node): void {
+        changes.replaceNode(sourceFile, token.parent, createKeywordTypeNode(SyntaxKind.UnknownKeyword));
+    }
+}
diff --git a/tests/cases/fourslash/convertToUnknownFirst.ts b/tests/cases/fourslash/convertToUnknownFirst.ts
new file mode 100644
index 0000000000000..d1ece7ddb3c03
--- /dev/null
+++ b/tests/cases/fourslash/convertToUnknownFirst.ts
@@ -0,0 +1,9 @@
+/// <reference path='fourslash.ts' />
+
+////0 as string;
+
+verify.codeFix({
+    description: "Replace '0' with '0 as unknown'",
+    index: 0,
+    newFileContent: "0 as unknown as string",
+});