diff --git a/Contrib/NSISdl/httpget.cpp b/Contrib/NSISdl/httpget.cpp
index fb18e881..3da73760 100644
--- a/Contrib/NSISdl/httpget.cpp
+++ b/Contrib/NSISdl/httpget.cpp
@@ -487,7 +487,7 @@ __int64 JNL_HTTPGet::content_length()
   char *p=getheader("content-length:");
   if (!p) return 0;
   __int64 cl = myatoi64(p);
-  if (cl > 0) return cl;
+  if (cl >= 0) return cl;
 
   // workaround for bug #1744091
   // some buggy apache servers return negative values for sizes