diff --git a/lib/sourcemap.js b/lib/sourcemap.js
index e5d7df60..3714027e 100644
--- a/lib/sourcemap.js
+++ b/lib/sourcemap.js
@@ -58,6 +58,16 @@ function SourceMap(options) {
         sourceRoot : options.root
     });
     var orig_map = options.orig && new MOZ_SourceMap.SourceMapConsumer(options.orig);
+
+    if (orig_map && Array.isArray(options.orig.sources)) {
+        options.orig.sources.forEach(function(source) {
+            var sourceContent = orig_map.sourceContentFor(source, true);
+            if (sourceContent) {
+                generator.setSourceContent(source, sourceContent);
+            }
+        });
+    }
+
     function add(source, gen_line, gen_col, orig_line, orig_col, name) {
         if (orig_map) {
             var info = orig_map.originalPositionFor({