diff --git a/test/fixtures/dependencies/expected.js b/test/fixtures/dependencies/expected.js
new file mode 100644
index 0000000..63f40f8
--- /dev/null
+++ b/test/fixtures/dependencies/expected.js
@@ -0,0 +1 @@
+export default "body{color:blue}body{color:#fff}body{color:red}";
diff --git a/test/fixtures/dependencies/index.js b/test/fixtures/dependencies/index.js
new file mode 100644
index 0000000..817010c
--- /dev/null
+++ b/test/fixtures/dependencies/index.js
@@ -0,0 +1,3 @@
+import style1 from './style1.scss';
+
+export default style1;
diff --git a/test/fixtures/dependencies/style1.scss b/test/fixtures/dependencies/style1.scss
new file mode 100644
index 0000000..6c75562
--- /dev/null
+++ b/test/fixtures/dependencies/style1.scss
@@ -0,0 +1,3 @@
+@import 'style2.scss';
+
+body {color: red;}
diff --git a/test/fixtures/dependencies/style2.scss b/test/fixtures/dependencies/style2.scss
new file mode 100644
index 0000000..b3623d7
--- /dev/null
+++ b/test/fixtures/dependencies/style2.scss
@@ -0,0 +1,3 @@
+@import 'style3.scss';
+
+body {color: white;}
diff --git a/test/fixtures/dependencies/style3.scss b/test/fixtures/dependencies/style3.scss
new file mode 100644
index 0000000..355275b
--- /dev/null
+++ b/test/fixtures/dependencies/style3.scss
@@ -0,0 +1 @@
+body {color:blue;}
diff --git a/test/index.test.ts b/test/index.test.ts
index a232f62..5d190f4 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -478,3 +478,68 @@ test('When `sourcemap` is set, to `true`, adjacent source map file should be out
         });
     });
 });
+
+test('module stylesheets graph should be added to watch list', t => {
+  const inputFilePath = 'test/fixtures/dependencies/index.js';
+
+  // Bundle our dependencies fixture module
+  // ----
+  return rollup({
+    input: inputFilePath,
+    plugins: [
+      sass({
+        options: sassOptions
+      })
+    ]
+  })
+    // Load nested style sheet contents and return associated list of filename and content tuples
+    // ----
+    .then(bundle => {
+      return Promise.all([
+          'test/fixtures/dependencies/style1.scss',
+          'test/fixtures/dependencies/style2.scss',
+          'test/fixtures/dependencies/style3.scss',
+        ]
+          .map(filePath => fs.readFile(filePath).then(buf => [filePath, squash(buf.toString())]))
+      )
+        // Run tests
+        // ----
+        .then(async nestedFilePathsAndContents => {
+          // Check `watchFiles` count (three above, and 'index.js' module one)
+          t.true(bundle.watchFiles.length === 4, 'should contain expected number of "watched" files');
+
+          // Ensure our initial 'index.js' module is being watched
+          t.true(bundle.watchFiles[0].endsWith(inputFilePath),
+            'Expected `bundle.watchFiles[0]` to end with "index.js"');
+
+          // Skip 'index.js' file and ensure remaining nested files are also watched.
+          // ----
+          bundle.watchFiles.slice(1).forEach((filePath, i) => {
+            const [expectedTail] = nestedFilePathsAndContents[i];
+            t.true(filePath.endsWith(expectedTail), `${filePath} should end with ${expectedTail}`);
+          });
+
+          // Get target module.
+          // ----
+          const targetModule = bundle?.cache?.modules[0];
+          t.true(!!targetModule, 'Expected bundle data');
+
+          // Ensure target module transform dependencies indeed end with expected file path tails.
+          // ----
+          t.true(targetModule.transformDependencies?.every((filePath, i) => {
+            const [expectedTail] = nestedFilePathsAndContents[i];
+            const result = filePath.endsWith(expectedTail);
+            t.true(result, `${filePath} should end with ${expectedTail}`);
+            return result;
+          }), '`bundle.cache.modules[0].transformDependencies` entries should' +
+            ' each end with expected file-path tails');
+
+          // Test final content output
+          // ----
+          const expectedFinalContent = await fs.readFile('test/fixtures/dependencies/expected.js')
+            .then(x => x.toString());
+
+          t.is(targetModule.code.trim(), expectedFinalContent.trim());
+        });
+    });
+});