diff --git a/build/pgo/js-input/sunspider/regexp-dna.html b/build/pgo/js-input/sunspider/regexp-dna.html
index a4902196736f..4a00399b8054 100644
--- a/build/pgo/js-input/sunspider/regexp-dna.html
+++ b/build/pgo/js-input/sunspider/regexp-dna.html
@@ -1741,14 +1741,14 @@ ilen = dnaInput.length;
 dnaInput = dnaInput.replace(/>.*\n|\n/g,"")
 clen = dnaInput.length
 
-var dnaOutputString;
+var dnaOutputString = "";
 
 for(i in seqs)
     dnaOutputString += seqs[i].source + " " + (dnaInput.match(seqs[i]) || []).length + "\n";
  // match returns null if no matches, so replace with empty
 
 for(k in subs)
- dnaInput = dnaInput.replace(k, subs[k], "g")
+ dnaInput = dnaInput.replace(k, subs[k]) // FIXME: Would like this to be a global substitution in a future version of SunSpider.
  // search string, replacement string, flags