diff --git a/packages/metro-config/src/defaults/index.js b/packages/metro-config/src/defaults/index.js
index 8ee4308daf..602776ccbe 100644
--- a/packages/metro-config/src/defaults/index.js
+++ b/packages/metro-config/src/defaults/index.js
@@ -70,7 +70,7 @@ const getDefaultValues = (projectRoot: ?string): ConfigT => ({
     customSerializer: null,
     isThirdPartyModule: module =>
       /(?:^|[/\\])node_modules[/\\]/.test(module.path),
-    unstable_allowIndexMap: false,
+    unstable_allowIndexMap: true,
   },
 
   server: {
@@ -136,7 +136,7 @@ const getDefaultValues = (projectRoot: ?string): ConfigT => ({
     unstable_disableNormalizePseudoGlobals: false,
     unstable_renameRequire: true,
     unstable_compactOutput: false,
-    unstable_compactSourceMaps: false,
+    unstable_compactSourceMaps: true,
     unstable_memoizeInlineRequires: false,
     unstable_workerThreads: false,
   },
diff --git a/packages/metro/src/integration_tests/__tests__/__snapshots__/buildGraph-test.js.snap b/packages/metro/src/integration_tests/__tests__/__snapshots__/buildGraph-test.js.snap
index 3be10525a9..52456009a1 100644
--- a/packages/metro/src/integration_tests/__tests__/__snapshots__/buildGraph-test.js.snap
+++ b/packages/metro/src/integration_tests/__tests__/__snapshots__/buildGraph-test.js.snap
@@ -24,394 +24,21 @@ Array [
         ],
       },
       "lineCount": 13,
-      "map": Array [
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-          2,
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-          2,
-          13,
-          0,
-        ],
-        Array [
-          4,
-          6,
-          13,
-          6,
+      "map": Object {
+        "mappings": ";EAUA,YAAY;;EAEZ,IAAMA,GAAG,GAAGC,WAAO,CAAAC,cAAA,GAAQ,CAAC;EAC5B,IAAMC,GAAG,GAAGF,WAAO,CAAAC,cAAA,GAAQ,CAAC;EAG5B,IAAME,UAAU,GAAGH,WAAO,CAAAC,cAAA,GAAe,CAAC;EAE1CG,MAAM,CAACC,IAAI,CAAAD,MAAA,CAAAE,MAAA,KAAKP,GAAG,CAAC,CAAC;EAErBQ,MAAM,CAACC,OAAO,GAAG;IAACN,GAAG,EAAHA,GAAG;IAAEH,GAAG,EAAHA,GAAG;IAAEI,UAAU,EAAVA;EAAU,CAAC;AAAC,G",
+        "names": Array [
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     "type": "js/module",
   },