diff --git a/plugins/experimental/multiplexer/dispatch.cc b/plugins/experimental/multiplexer/dispatch.cc
index 2ef49d0df45..911bb1aea68 100644
--- a/plugins/experimental/multiplexer/dispatch.cc
+++ b/plugins/experimental/multiplexer/dispatch.cc
@@ -35,16 +35,21 @@ extern Statistics statistics;
 
 extern size_t timeout;
 
-Request::Request(const std::string &h, const TSMBuffer b, const TSMLoc l)
-  : host(h), length(TSHttpHdrLengthGet(b, l)), io(new ats::io::IO())
+Request::Request(const std::string &h, const TSMBuffer b, const TSMLoc l) : host(h), length(0), io(new ats::io::IO())
 {
   assert(!host.empty());
   assert(b != NULL);
   assert(l != NULL);
-  assert(length > 0);
   assert(io.get() != NULL);
   TSHttpHdrPrint(b, l, io->buffer);
-  assert(length == TSIOBufferReaderAvail(io->reader));
+  length = TSIOBufferReaderAvail(io->reader);
+  assert(length > 0);
+  /*
+   * TSHttpHdrLengthGet returns the size with possible "internal" headers
+   * which are not printed by TSHttpHdrPrint.
+   * Therefore the greater than or equal comparisson
+  */
+  assert(TSHttpHdrLengthGet(b, l) >= length);
 }
 
 Request::Request(const Request &r) : host(r.host), length(r.length), io(const_cast<Request &>(r).io.release())