diff --git a/packages/compiler-cli/ngcc/src/main.ts b/packages/compiler-cli/ngcc/src/main.ts
index b359b9af5b..3e9d6cec11 100644
--- a/packages/compiler-cli/ngcc/src/main.ts
+++ b/packages/compiler-cli/ngcc/src/main.ts
@@ -65,7 +65,7 @@ const SUPPORTED_FORMATS: EntryPointFormat[] = ['esm5', 'esm2015'];
 export function mainNgcc(
     {basePath, targetEntryPointPath, propertiesToConsider = SUPPORTED_FORMAT_PROPERTIES,
      compileAllFormats = true, createNewEntryPointFormats = false}: NgccOptions): void {
-  const transformer = new Transformer(basePath, basePath);
+  const transformer = new Transformer(basePath);
   const host = new DependencyHost();
   const resolver = new DependencyResolver(host);
   const finder = new EntryPointFinder(resolver);
diff --git a/packages/compiler-cli/ngcc/src/packages/transformer.ts b/packages/compiler-cli/ngcc/src/packages/transformer.ts
index 1cf50fa860..f46312d3e9 100644
--- a/packages/compiler-cli/ngcc/src/packages/transformer.ts
+++ b/packages/compiler-cli/ngcc/src/packages/transformer.ts
@@ -45,7 +45,7 @@ import {EntryPointBundle} from './entry_point_bundle';
  * - Some formats may contain multiple "modules" in a single file.
  */
 export class Transformer {
-  constructor(private sourcePath: string, private targetPath: string) {}
+  constructor(private sourcePath: string) {}
 
   /**
    * Transform the source (and typings) files of a bundle.
@@ -84,9 +84,9 @@ export class Transformer {
   getRenderer(host: NgccReflectionHost, isCore: boolean, bundle: EntryPointBundle): Renderer {
     switch (bundle.format) {
       case 'esm2015':
-        return new EsmRenderer(host, isCore, bundle, this.sourcePath, this.targetPath);
+        return new EsmRenderer(host, isCore, bundle, this.sourcePath);
       case 'esm5':
-        return new Esm5Renderer(host, isCore, bundle, this.sourcePath, this.targetPath);
+        return new Esm5Renderer(host, isCore, bundle, this.sourcePath);
       default:
         throw new Error(`Renderer for "${bundle.format}" not yet implemented.`);
     }
diff --git a/packages/compiler-cli/ngcc/src/rendering/esm5_renderer.ts b/packages/compiler-cli/ngcc/src/rendering/esm5_renderer.ts
index 8c68a68704..382b1ff1c8 100644
--- a/packages/compiler-cli/ngcc/src/rendering/esm5_renderer.ts
+++ b/packages/compiler-cli/ngcc/src/rendering/esm5_renderer.ts
@@ -15,9 +15,8 @@ import {EntryPointBundle} from '../packages/entry_point_bundle';
 
 export class Esm5Renderer extends EsmRenderer {
   constructor(
-      host: NgccReflectionHost, isCore: boolean, bundle: EntryPointBundle, sourcePath: string,
-      targetPath: string) {
-    super(host, isCore, bundle, sourcePath, targetPath);
+      host: NgccReflectionHost, isCore: boolean, bundle: EntryPointBundle, sourcePath: string) {
+    super(host, isCore, bundle, sourcePath);
   }
 
   /**
diff --git a/packages/compiler-cli/ngcc/src/rendering/esm_renderer.ts b/packages/compiler-cli/ngcc/src/rendering/esm_renderer.ts
index fd38bb8333..45cf8da203 100644
--- a/packages/compiler-cli/ngcc/src/rendering/esm_renderer.ts
+++ b/packages/compiler-cli/ngcc/src/rendering/esm_renderer.ts
@@ -17,9 +17,8 @@ import {isDtsPath} from '../../../src/ngtsc/util/src/typescript';
 
 export class EsmRenderer extends Renderer {
   constructor(
-      host: NgccReflectionHost, isCore: boolean, bundle: EntryPointBundle, sourcePath: string,
-      targetPath: string) {
-    super(host, isCore, bundle, sourcePath, targetPath);
+      host: NgccReflectionHost, isCore: boolean, bundle: EntryPointBundle, sourcePath: string) {
+    super(host, isCore, bundle, sourcePath);
   }
 
   /**
diff --git a/packages/compiler-cli/ngcc/src/rendering/renderer.ts b/packages/compiler-cli/ngcc/src/rendering/renderer.ts
index 2345588b56..964c27ec47 100644
--- a/packages/compiler-cli/ngcc/src/rendering/renderer.ts
+++ b/packages/compiler-cli/ngcc/src/rendering/renderer.ts
@@ -81,8 +81,7 @@ export const RedundantDecoratorMap = Map;
 export abstract class Renderer {
   constructor(
       protected host: NgccReflectionHost, protected isCore: boolean,
-      protected bundle: EntryPointBundle, protected sourcePath: string,
-      protected targetPath: string) {}
+      protected bundle: EntryPointBundle, protected sourcePath: string) {}
 
   renderProgram(
       decorationAnalyses: DecorationAnalyses, switchMarkerAnalyses: SwitchMarkerAnalyses,
@@ -333,7 +332,7 @@ export abstract class Renderer {
     const outputPath = resolve(this.targetPath, relative(this.sourcePath, sourceFile.fileName));
     const outputMapPath = `${outputPath}.map`;
     const outputMap = output.generateMap({
-      source: sourceFile.fileName,
+      source: outputPath,
       includeContent: true,
       // hires: true // TODO: This results in accurate but huge sourcemaps. Instead we should fix
       // the merge algorithm.
diff --git a/packages/compiler-cli/ngcc/test/rendering/esm2015_renderer_spec.ts b/packages/compiler-cli/ngcc/test/rendering/esm2015_renderer_spec.ts
index 9176141ae1..21763076b1 100644
--- a/packages/compiler-cli/ngcc/test/rendering/esm2015_renderer_spec.ts
+++ b/packages/compiler-cli/ngcc/test/rendering/esm2015_renderer_spec.ts
@@ -28,7 +28,7 @@ function setup(file: {name: string, contents: string}) {
           referencesRegistry, [AbsoluteFsPath.fromUnchecked('/')], false)
           .analyzeProgram();
   const switchMarkerAnalyses = new SwitchMarkerAnalyzer(host).analyzeProgram(bundle.src.program);
-  const renderer = new EsmRenderer(host, false, bundle, dir, dir);
+  const renderer = new EsmRenderer(host, false, bundle, dir);
   return {
     host,
     program: bundle.src.program,
diff --git a/packages/compiler-cli/ngcc/test/rendering/esm5_renderer_spec.ts b/packages/compiler-cli/ngcc/test/rendering/esm5_renderer_spec.ts
index 2c025e7b7a..8fd45339aa 100644
--- a/packages/compiler-cli/ngcc/test/rendering/esm5_renderer_spec.ts
+++ b/packages/compiler-cli/ngcc/test/rendering/esm5_renderer_spec.ts
@@ -28,7 +28,7 @@ function setup(file: {name: string, contents: string}) {
           referencesRegistry, [AbsoluteFsPath.fromUnchecked('/')], false)
           .analyzeProgram();
   const switchMarkerAnalyses = new SwitchMarkerAnalyzer(host).analyzeProgram(bundle.src.program);
-  const renderer = new Esm5Renderer(host, false, bundle, dir, dir);
+  const renderer = new Esm5Renderer(host, false, bundle, dir);
   return {
     host,
     program: bundle.src.program,
diff --git a/packages/compiler-cli/ngcc/test/rendering/renderer_spec.ts b/packages/compiler-cli/ngcc/test/rendering/renderer_spec.ts
index b945d60351..c933a04894 100644
--- a/packages/compiler-cli/ngcc/test/rendering/renderer_spec.ts
+++ b/packages/compiler-cli/ngcc/test/rendering/renderer_spec.ts
@@ -21,7 +21,7 @@ import {makeTestEntryPointBundle} from '../helpers/utils';
 
 class TestRenderer extends Renderer {
   constructor(host: Esm2015ReflectionHost, isCore: boolean, bundle: EntryPointBundle) {
-    super(host, isCore, bundle, '/src', '/dist');
+    super(host, isCore, bundle, '/src');
   }
   addImports(output: MagicString, imports: {specifier: string, qualifier: string}[]) {
     output.prepend('\n// ADD IMPORTS\n');