diff --git a/index.js b/index.js
index aa200d7..7bcbef0 100644
--- a/index.js
+++ b/index.js
@@ -33,6 +33,20 @@ module.exports = function parse (modules, opts) {
     return duplexer(concat(function (buf) {
         try {
             body = buf.toString('utf8').replace(/^#!/, '//#!');
+            var matches = false;
+            for (var key in modules) {
+                if (body.indexOf(key) !== -1) {
+                    matches = true;
+                    break;
+                }
+            }
+
+            if (!matches) {
+                // just pass it through
+                output.end(buf);
+                return;
+            }
+
             if (opts.sourceMap) {
                 inputMap = convertSourceMap.fromSource(body);
                 if (inputMap) inputMap = inputMap.toObject();
@@ -40,11 +54,7 @@ module.exports = function parse (modules, opts) {
                 sourcemapper = new MagicString(body);
             }
 
-            for (var key in modules) {
-                if (body.indexOf(key) === -1) continue;
-                falafel(body, parserOpts, walk);
-                break;
-            }
+            falafel(body, parserOpts, walk);
         }
         catch (err) { return error(err) }
         finish(body);
diff --git a/test/sourcemap.js b/test/sourcemap.js
index bb00d45..56be1ce 100644
--- a/test/sourcemap.js
+++ b/test/sourcemap.js
@@ -84,5 +84,43 @@ test('input source map', function (t) {
         t.equal(mapped.column, 0);
     }));
 
+    transform.end(minified.code);
+});
+
+test('retain input source map when file has no static-module use', function (t) {
+    t.plan(4);
+
+    var content = fs.readFileSync(__dirname + '/sourcemap/main.js', 'utf8');
+    var minified = uglify.minify({ 'main.js': content }, {
+        output: { beautify: true },
+        sourceMap: {
+            url: 'inline',
+            includeSources: true
+        }
+    });
+
+    var transform = staticModule({
+        not_sheetify: function () { return 'whatever'; }
+    }, { sourceMap: true, inputFilename: 'main.js' });
+
+    transform.pipe(concat({ encoding: 'string' }, function (res) {
+        var consumer = new SourceMapConsumer(convertSourceMap.fromSource(res).toObject());
+
+        var mapped = consumer.originalPositionFor({
+            line: 7,
+            column: 0
+        });
+        t.equal(mapped.line, 8);
+        t.equal(mapped.column, 0);
+
+        mapped = consumer.originalPositionFor({
+            line: 7,
+            column: 21
+        });
+        t.equal(mapped.line, 10);
+        t.equal(mapped.column, 0);
+    }));
+
+
     transform.end(minified.code);
 });