--- a/src/http/ngx_http_request_body.c
+++ b/src/http/ngx_http_request_body.c
@@ -15,6 +15,7 @@ static ngx_int_t ngx_http_write_request_
     ngx_chain_t *body);
 static void ngx_http_read_discarded_request_body_handler(ngx_http_request_t *r);
 static ngx_int_t ngx_http_read_discarded_request_body(ngx_http_request_t *r);
+static ngx_int_t ngx_http_test_expect(ngx_http_request_t *r);
 
 
 /*
@@ -41,6 +42,10 @@ ngx_http_read_client_request_body(ngx_ht
         return NGX_OK;
     }
 
+    if (ngx_http_test_expect(r) != NGX_OK) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
     rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
     if (rb == NULL) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
@@ -433,6 +438,10 @@ ngx_http_discard_request_body(ngx_http_r
         return NGX_OK;
     }
 
+    if (ngx_http_test_expect(r) != NGX_OK) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
     rev = r->connection->read;
 
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0, "http set discard body");
@@ -581,3 +590,45 @@ ngx_http_read_discarded_request_body(ngx
 
     return NGX_AGAIN;
 }
+
+
+static ngx_int_t
+ngx_http_test_expect(ngx_http_request_t *r)
+{
+    ngx_int_t   n;
+    ngx_str_t  *expect;
+
+    if (r->expect_tested
+        || r->headers_in.expect == NULL
+        || r->http_version < NGX_HTTP_VERSION_11)
+    {
+        return NGX_OK;
+    }
+
+    r->expect_tested = 1;
+
+    expect = &r->headers_in.expect->value;
+
+    if (expect->len != sizeof("100-continue") - 1
+        || ngx_strncasecmp(expect->data, (u_char *) "100-continue",
+                           sizeof("100-continue") - 1)
+           != 0)
+    {
+        return NGX_OK;
+    }
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "send 100 Continue");
+
+    n = r->connection->send(r->connection,
+                            (u_char *) "HTTP/1.1 100 Continue" CRLF CRLF,
+                            sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1);
+
+    if (n == sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1) {
+        return NGX_OK;
+    }
+
+    /* we assume that such small packet should be send successfully */
+
+    return NGX_ERROR;
+}