diff --git a/lib/sourcemap.js b/lib/sourcemap.js
index 663ef12e..15353476 100644
--- a/lib/sourcemap.js
+++ b/lib/sourcemap.js
@@ -70,7 +70,9 @@ function SourceMap(options) {
             source = info.source;
             orig_line = info.line;
             orig_col = info.column;
-            name = info.name;
+            if (info.name) {
+                name = info.name;
+            }
         }
         generator.addMapping({
             generated : { line: gen_line + options.dest_line_diff, column: gen_col },