diff --git a/README.md b/README.md
index fc0bf39..4de6df1 100644
--- a/README.md
+++ b/README.md
@@ -89,7 +89,13 @@ module.exports = function(config) {
         }
       },
 
-      verbose: true // output config used by istanbul for debugging
+      verbose: true, // output config used by istanbul for debugging
+
+      // `instrumentation` is used to configure Istanbul API package.
+      instrumentation: {
+        // To include `node_modules` code in the report.
+        'default-excludes': false
+      }
     }
   });
 };
diff --git a/src/reporter.js b/src/reporter.js
index 7645a6b..5b77c28 100644
--- a/src/reporter.js
+++ b/src/reporter.js
@@ -82,6 +82,7 @@ function CoverageIstanbulReporter(baseReporterDecorator, logger, config) {
         : {};
 
     const reportConfig = istanbul.config.loadObject({
+      instrumentation: Object.assign({}, coverageConfig.instrumentation),
       verbose: coverageConfig.verbose === true,
       reporting: Object.assign({}, coverageConfig, reportConfigOverride)
     });