--- a/netwerk/base/nsSimpleURI.cpp
+++ b/netwerk/base/nsSimpleURI.cpp
@@ -690,22 +690,22 @@ nsSimpleURI::CloneInternal(nsSimpleURI::
 NS_IMETHODIMP
 nsSimpleURI::Resolve(const nsACString &relativePath, nsACString &result)
 {
     result = relativePath;
     return NS_OK;
 }
 
 NS_IMETHODIMP
-nsSimpleURI::GetAsciiSpec(nsACString &result)
+nsSimpleURI::GetAsciiSpec(nsACString &aResult)
 {
-    nsAutoCString buf;
-    nsresult rv = GetSpec(buf);
+    nsresult rv = GetSpec(aResult);
     if (NS_FAILED(rv)) return rv;
-    return NS_EscapeURL(buf, esc_OnlyNonASCII|esc_AlwaysCopy, result, fallible);
+    MOZ_ASSERT(IsASCII(aResult), "The spec should be ASCII");
+    return NS_OK;
 }
 
 NS_IMETHODIMP
 nsSimpleURI::GetAsciiHostPort(nsACString &result)
 {
     // XXX This behavior mimics GetHostPort.
     return NS_ERROR_FAILURE;
 }