diff --git a/lib/chibi/net.scm b/lib/chibi/net.scm
index 5895994c..12bdf2b5 100644
--- a/lib/chibi/net.scm
+++ b/lib/chibi/net.scm
@@ -29,7 +29,7 @@
 ;;> values on success - the socket, an input port, and an
 ;;> output port - or \scheme{#f} on failure.
 
-(define (open-net-io host service)
+(define (open-net-io host service . o)
   (let lp ((addr (get-address-info host service)))
     (if (not addr)
         (error "couldn't find address" host service)
@@ -46,7 +46,11 @@
                 (lp (address-info-next addr)))
                (else
                 (cond-expand
-                 (threads (set-file-descriptor-status! sock open/non-block))
+                 (threads
+                  (if (not (and (pair? o) (car o)))
+                      (let ((st (bitwise-and (get-file-descriptor-status sock)
+                                             open/non-block)))
+                        (set-file-descriptor-status! sock st))))
                  (else #f))
                 (list sock
                       (open-input-file-descriptor sock #t)
diff --git a/lib/chibi/net.sld b/lib/chibi/net.sld
index 011d954c..19b756cc 100644
--- a/lib/chibi/net.sld
+++ b/lib/chibi/net.sld
@@ -21,6 +21,6 @@
           get-peer-name
           ;; C structs
           sockaddr addrinfo)
-  (import (chibi) (chibi filesystem))
+  (import (chibi) (chibi filesystem) (srfi 33))
   (include-shared "net")
   (include "net.scm"))
diff --git a/lib/chibi/net/http.scm b/lib/chibi/net/http.scm
index bb12be88..d05aa735 100644
--- a/lib/chibi/net/http.scm
+++ b/lib/chibi/net/http.scm
@@ -165,7 +165,8 @@
             (let* ((io (open-net-io
                         host
                         (or (uri-port uri)
-                            (if (eq? 'https (uri-scheme uri)) 443 80))))
+                            (if (eq? 'https (uri-scheme uri)) 443 80))
+                        (assq-ref in-headers 'blocking)))
                    (in (cadr io))
                    (out (car (cddr io))))
               (display method out)
@@ -180,8 +181,10 @@
                 (display "\r\n" out)))
               (for-each
                (lambda (x)
-                 (display (car x) out)  (display ": " out)
-                 (display (cdr x) out) (display "\r\n" out))
+                 (cond
+                  ((not (eq? 'blocking (car x)))
+                   (display (car x) out)  (display ": " out)
+                   (display (cdr x) out) (display "\r\n" out))))
                in-headers)
               (display "Connection: close\r\n\r\n" out)
               (http-send-body in-headers body out)
diff --git a/lib/chibi/snow/commands.scm b/lib/chibi/snow/commands.scm
index 5fdfe5f6..785f8264 100644
--- a/lib/chibi/snow/commands.scm
+++ b/lib/chibi/snow/commands.scm
@@ -766,29 +766,33 @@
 ;; a subset of http-post functionality that can shell out to curl
 ;; depending on config
 (define (snow-post cfg uri params)
-  (if (conf-get cfg 'use-curl?)
-      (let ((cmd `(curl --silent
-                        ,@(append-map
-                           (lambda (x)
-                             (cond
-                              ((and (pair? (cdr x)) (assq 'value (cdr x)))
-                               => (lambda (y)
-                                    `("-F" ,(string-append
-                                             (display-to-string (car x)) "="
-                                             (display-to-string (cdr y))))))
-                              ((and (pair? (cdr x)) (assq 'file (cdr x)))
-                               => (lambda (y)
-                                    `("-F" ,(string-append
-                                             (display-to-string (car x)) "=@"
-                                             (display-to-string (cdr y))))))
-                              (else
-                               `("-F" ,(string-append
-                                        (display-to-string (car x)) "="
-                                        (display-to-string (cdr x)))))))
-                           params)
-                        ,(uri->string uri))))
-        (open-input-bytevector (process->bytevector cmd)))
-      (http-post uri params)))
+  (cond
+   ((conf-get cfg 'use-curl?)
+    (let ((cmd `(curl --silent
+                      ,@(append-map
+                         (lambda (x)
+                           (cond
+                            ((and (pair? (cdr x)) (assq 'value (cdr x)))
+                             => (lambda (y)
+                                  `("-F" ,(string-append
+                                           (display-to-string (car x)) "="
+                                           (display-to-string (cdr y))))))
+                            ((and (pair? (cdr x)) (assq 'file (cdr x)))
+                             => (lambda (y)
+                                  `("-F" ,(string-append
+                                           (display-to-string (car x)) "=@"
+                                           (display-to-string (cdr y))))))
+                            (else
+                             `("-F" ,(string-append
+                                      (display-to-string (car x)) "="
+                                      (display-to-string (cdr x)))))))
+                         params)
+                      ,(uri->string uri))))
+      (open-input-bytevector (process->bytevector cmd))))
+   ((not (conf-get cfg 'non-blocking-io))
+    (http-post uri params '((blocking . #t))))
+   (else
+    (http-post uri params))))
 
 (define (remote-command cfg name path params)
   (let ((uri (remote-uri cfg name path)))