diff --git a/types/apollo-codegen/apollo-codegen-tests.ts b/types/apollo-codegen/apollo-codegen-tests.ts
index 38d9733faf..2c78f26fa9 100644
--- a/types/apollo-codegen/apollo-codegen-tests.ts
+++ b/types/apollo-codegen/apollo-codegen-tests.ts
@@ -14,7 +14,7 @@ async function main() {
         "POST"
     );
 
-    generate(["input.ts"], "schema.json", "types.ts", "typescript", "gql", {
+    generate(["input.ts"], "schema.json", "types.ts", "", "typescript", "gql", "", {
         passthroughCustomScalars: false,
         customScalarsPrefix: "S",
         addTypename: false,
diff --git a/types/apollo-codegen/index.d.ts b/types/apollo-codegen/index.d.ts
index a506f7475e..1372739066 100644
--- a/types/apollo-codegen/index.d.ts
+++ b/types/apollo-codegen/index.d.ts
@@ -1,13 +1,15 @@
-// Type definitions for apollo-codegen 0.16
+// Type definitions for apollo-codegen 0.20
 // Project: https://github.com/apollographql/apollo-codegen
-// Definitions by: Bradley Ayers <https://github.com/bradleyayers>
+// Definitions by: Bradley Ayers <https://github.com/bradleyayers>, Maria Carrasco <https://github.com/kostspielig>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.3
 
+import { Options } from 'graphql/utilities/schemaPrinter';
+
 export function downloadSchema(
     url: string,
     outputPath: string,
-    additionalHeaders: { [name: string]: string },
+    additionalHeaders: { [name: string]: string; },
     insecure: boolean,
     method: string
 ): Promise<void>;
@@ -19,22 +21,19 @@ export function introspectSchema(
 
 export function printSchema(
     schemaPath: string,
-    outputPath: string
+    outputPath: string,
+    options?: Options
 ): Promise<void>;
 
+export type TargetType = 'json' | 'swift' | 'ts-legacy' | 'typescript-legacy' | 'flow-legacy' | 'scala' | 'flow' | 'typescript' | 'ts';
+
 export function generate(
     inputPaths: string[],
     schemaPath: string,
     outputPath: string,
-    target: "json" | "swift" | "ts" | "typescript" | "flow" | "scala",
+    only: string,
+    target: TargetType,
     tagName: string,
-    options: {
-        passthroughCustomScalars: boolean;
-        customScalarsPrefix: string;
-        addTypename: boolean;
-        namespace: string;
-        operationIdsPath: string | null;
-        generateOperationIds: boolean;
-        mergeInFieldsFromFragmentSpreads: boolean;
-    }
+    projectName: string,
+    options: any
 ): void;