diff --git a/src/tool_cb_hdr.c b/src/tool_cb_hdr.c
index af9bb87eac3dff16cf76b654329f202621d691b1..fd208e862ceab7a4c4b130d8b25d400448164165 100644
--- a/src/tool_cb_hdr.c
+++ b/src/tool_cb_hdr.c
@@ -75,6 +75,8 @@ size_t tool_header_cb(void *ptr, size_t size, size_t nmemb, void *userdata)
     size_t rc = fwrite(ptr, size, nmemb, heads->stream);
     if(rc != cb)
       return rc;
+    /* flush the stream to send off what we got earlier */
+    (void)fflush(heads->stream);
   }
 
   /*