diff --git a/src/NodeParser/MappedTypeNodeParser.ts b/src/NodeParser/MappedTypeNodeParser.ts
index 1a9bbcd04..bae958e05 100644
--- a/src/NodeParser/MappedTypeNodeParser.ts
+++ b/src/NodeParser/MappedTypeNodeParser.ts
@@ -10,13 +10,14 @@ import { LiteralType } from "../Type/LiteralType";
 import { NumberType } from "../Type/NumberType";
 import { ObjectProperty, ObjectType } from "../Type/ObjectType";
 import { StringType } from "../Type/StringType";
+import { SymbolType } from "../Type/SymbolType";
 import { UnionType } from "../Type/UnionType";
+import assert from "../Utils/assert";
 import { derefAnnotatedType, derefType } from "../Utils/derefType";
 import { getKey } from "../Utils/nodeKey";
+import { notUndefined } from "../Utils/notUndefined";
 import { preserveAnnotation } from "../Utils/preserveAnnotation";
 import { removeUndefined } from "../Utils/removeUndefined";
-import { notUndefined } from "../Utils/notUndefined";
-import { SymbolType } from "../Type/SymbolType";
 
 export class MappedTypeNodeParser implements SubNodeParser {
     public constructor(protected childNodeParser: NodeParser, protected readonly additionalProperties: boolean) {}
@@ -67,11 +68,23 @@ export class MappedTypeNodeParser implements SubNodeParser {
         }
     }
 
+    protected mapKey(node: ts.MappedTypeNode, rawKey: LiteralType, context: Context): LiteralType {
+        if (!node.nameType) {
+            return rawKey;
+        }
+        const key = derefType(
+            this.childNodeParser.createType(node.nameType, this.createSubContext(node, rawKey, context))
+        );
+        assert(key instanceof LiteralType, "Must resolve to Literal");
+        return key;
+    }
+
     protected getProperties(node: ts.MappedTypeNode, keyListType: UnionType, context: Context): ObjectProperty[] {
         return keyListType
             .getTypes()
             .filter((type) => type instanceof LiteralType)
             .reduce((result: ObjectProperty[], key: LiteralType) => {
+                const namedKey = this.mapKey(node, key, context);
                 const propertyType = this.childNodeParser.createType(
                     node.type!,
                     this.createSubContext(node, key, context)
@@ -90,7 +103,7 @@ export class MappedTypeNodeParser implements SubNodeParser {
                 }
 
                 const objectProperty = new ObjectProperty(
-                    key.getValue().toString(),
+                    namedKey.getValue().toString(),
                     preserveAnnotation(propertyType, newType),
                     !node.questionToken && !hasUndefined
                 );
diff --git a/test/valid-data-type.test.ts b/test/valid-data-type.test.ts
index a1abf173c..a05bc9c3d 100644
--- a/test/valid-data-type.test.ts
+++ b/test/valid-data-type.test.ts
@@ -76,6 +76,8 @@ describe("valid-data-type", () => {
     it("type-keyof-object-function", assertValidSchema("type-keyof-object-function", "MyType"));
     it("type-mapped-simple", assertValidSchema("type-mapped-simple", "MyObject"));
     it("type-mapped-index", assertValidSchema("type-mapped-index", "MyObject"));
+    it("type-mapped-index-as", assertValidSchema("type-mapped-index-as", "MyObject"));
+    it("type-mapped-index-as-template", assertValidSchema("type-mapped-index-as-template", "MyObject"));
     it("type-mapped-literal", assertValidSchema("type-mapped-literal", "MyObject"));
     it("type-mapped-generic", assertValidSchema("type-mapped-generic", "MyObject"));
     it("type-mapped-native", assertValidSchema("type-mapped-native", "MyObject"));
diff --git a/test/valid-data/type-mapped-index-as-template/main.ts b/test/valid-data/type-mapped-index-as-template/main.ts
new file mode 100644
index 000000000..00a268183
--- /dev/null
+++ b/test/valid-data/type-mapped-index-as-template/main.ts
@@ -0,0 +1,9 @@
+interface Message {
+    id: number;
+    name: string;
+    title: string;
+}
+
+export type MyObject = {
+    [K in keyof Message as `message${Capitalize<K>}`]: Message[K];
+};
diff --git a/test/valid-data/type-mapped-index-as-template/schema.json b/test/valid-data/type-mapped-index-as-template/schema.json
new file mode 100644
index 000000000..3d2b5d218
--- /dev/null
+++ b/test/valid-data/type-mapped-index-as-template/schema.json
@@ -0,0 +1,26 @@
+{
+  "$ref": "#/definitions/MyObject",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "MyObject": {
+      "additionalProperties": false,
+      "properties": {
+        "messageId": {
+          "type": "number"
+        },
+        "messageName": {
+          "type": "string"
+        },
+        "messageTitle": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "messageId",
+        "messageName",
+        "messageTitle"
+      ],
+      "type": "object"
+    }
+  }
+}
diff --git a/test/valid-data/type-mapped-index-as/main.ts b/test/valid-data/type-mapped-index-as/main.ts
new file mode 100644
index 000000000..6c8601d6a
--- /dev/null
+++ b/test/valid-data/type-mapped-index-as/main.ts
@@ -0,0 +1,8 @@
+interface SomeInterface {
+    foo: 12;
+    bar: "baz";
+}
+
+export type MyObject = {
+    [K in keyof SomeInterface as Capitalize<K>]: `${K}.${SomeInterface[K]}`;
+};
diff --git a/test/valid-data/type-mapped-index-as/schema.json b/test/valid-data/type-mapped-index-as/schema.json
new file mode 100644
index 000000000..ae5209fb1
--- /dev/null
+++ b/test/valid-data/type-mapped-index-as/schema.json
@@ -0,0 +1,24 @@
+{
+  "$ref": "#/definitions/MyObject",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "MyObject": {
+      "additionalProperties": false,
+      "properties": {
+        "Bar": {
+          "const": "bar.baz",
+          "type": "string"
+        },
+        "Foo": {
+          "const": "foo.12",
+          "type": "string"
+        }
+      },
+      "required": [
+        "Foo",
+        "Bar"
+      ],
+      "type": "object"
+    }
+  }
+}